POTW #4 Grade 8 Solution:
POTW #4 Grade 7 Solution:
POTW #5 Grade 7/8 Question:
Jilly and Jolly were bored during math class (and were waiting to leach data off of others), so they decided to entertain themselves. They wanted to see which boy had the longest hair (measurements may not be accurate). They measured and found this data:
7cm, 4cm, 5cm
5cm, 15cm, 14cm
7cm, 16cm, 2cm,
4cm, 2cm, 9cm,
5cm, 6cm, 4cm,
6cm, 9cm
Find the mean and mode of the data as well as the range. Jilly and Jolly have decided to then go measure the hair lengths of the neighboring class. They predict that the 5 boys in that class will lift the mean by 2cm. What is the total amount of hair the boys in the neighboring class have?
Who do you think had the longest hair? The shortest? Reply with your answers to the comment section below in the POTW #5 thread.
Who do you think had the longest hair? The shortest? Reply with your answers to the comment section below in the POTW #5 thread.
Aleks
|
Fred
|
Stanley
|
Ethan
|
Maxwell
|
Nick
|
Yoav
|
Alan
|
Ryan
|
Can
|
Cole. S
|
Mathew
|
Ivan
|
Richard
|
Mateo
|
Derek
|
Dhruv
|
+BONUS QUESTION FOR PEOPLE NOT IN MRS.FAIRBARN’S CLASS
Who do you think are Jilly & Jolly without previous knowledge of who used their own precious time in completing this experiment and posing this GREAT POTW?
Grade 7/8 POTW:
ReplyDeleteFirst of all, Richard has the longest hair. Either Derek or Maxwell is second.
The mean is 7.0588, since we have a total of 120cm and the number of people is 17.
The mode is a tie between 5 cm and 4 cm because there are three people each with that length.
The range is 16-2 = 14 cm.
If the five boys lift the mean up by 2 cm, I will first round 7.0 something to 7, since I want to keep it as an integer. If they raise it by 2 cm, this means that all 17+5 = 22 of them have a mean of about 9. Right now, the total is 17*7 = 119 cm, while after the five boys are measured the total is 198 cm. This means that the five boys have a total of 79 cm.
-Alan
This is a very interesting question. Instead of listing the facts first, I'll list the questions!
ReplyDelete- Find mean, mode and range
- Total amount of hair neighbouring class has
- Predict longest and shortest length of hair
- Who made the question
Okay, I'll do one at a time. I'll list the facts needed for the beginning:
7cm, 4cm, 5cm, 5cm, 15cm, 14cm, 7cm, 16cm, 2cm, 4cm, 2cm, 9cm, 5cm, 6cm, 4cm,
6cm, 9cm
There are 2 (2s). There are 3 (4s). There are 3 (5s). There are 2 (6s). There are 2 (7s). There are 2 (9s). There is 1 (13). There is 1 (15). There is 1 (16).
The mode is therefore 4 and 5 cm.
There are 17 numbers. After adding them all together, the sum is 119. 119 divided by 17 is 7.
The mean is therefore 7 cm.
The largest number is 16 and the smallest is 2. 16-2=14.
The range is therefore 14 cm.
Now for the second question, the total amount of hair the neighboring class has. Here are the facts and I will use the data from the previous question too.
- Current sum is 119, current mean is 7, old number of people is 17
- New mean=old mean+2
- +5 people
Back to the math.
The old mean is 7. 7+2=9. The new mean must be 9. The old number of people is 17. 17+5=22. 9x22=198. Now subtract the old sum from the new sum. 198-119=79.
The total amount is therefore 79 cm.
The next questions here on out just needs 2 things. Logic. And knowing your peers.
Okay, I'm now going to separate the people into sections.
Long: Cole, Aleks, Maxwell, possibly Ivan. I said possibly so he probably doesn't belong. Cole, Aleks, Maxwell are the people I am imagining long hair for now and it is pretty hard to imaging multiple lengths at once, but I believe this is right or close.
Short: This is hard. It's hard to compare people with short hair when constant hair cuts are happening and most people have short hair, but I'll try. I won't include people I know won't fit. Process of elimination (i could be wrong):
Fred-Stanley, Stanley-Ethan, Ethan-Nick, Ethan-Yoav (I'll just say Yoav has shorter for now), Yoav-Alan (I believe Alan got a recent hair cut (don't fully remember)), Alan-Ryan, Alan-Can, Alan-Mathew, Alan-Richard, Alan-Mateo (ummmmmmmm Mateo? we'll go with that), Mateo-Derek, Mateo Dhruv
Once again Mateo??????? Okay. That doesn't seem right, but let's go with that. I will re-do this part after having another look.
Mateo shortest and back to longest. Aleks' hair is shorter I think. Cole and Maxwell are... Tied. I'll fix that up too!
Mateo Short
Maxwell and Cole Long
Okay. The last interesting question. Who is Jilly and Jolly?
Jilly and Jolly are boys. They made the question together. Must be a pair of close friends. Or even Math lovers.
The first thing I think of. It's either Aleks and Max (pretty close I think), or Alan and Fred. Knowing Alan and Fred, they would love to make a question, but not trying to be offensive, but Fred didn't do a single POTW yet. He isn't dedicated. It must be someone who is dedicated right? Aleks and Maxwell occasionally do it. They had a year to get used to POTW and the grade 7s wouldn't instantly go to that. Also, I KNOW it has to be Aleks and Max. Not 100%, but look at that picture up there. It's there for no reason unless Mr Milette personally put it in, but no. Looking at that picture up there with that man, my guess is Aleks and Max, period.
Work done with Cindy
DeleteI MADE A MISTAKE WAS MY COMMENT TOO LONG!!!
ReplyDeleteBhavee's POTW #5
ReplyDeleteFor the mean, median, mode and range of the boys hair length in Jolly and Jilly's class the mean would be 7.058, median would be 6 and mode would be a tie between 4 and 5 with 3 appearances each. The range is 14 because 16 which is the longest hair in the data set minus 2, which is the shortest hair in the data set is 14. In the neighbouring class however,the 5 boys who raised the mean by 2cm, caused it be 9.058. The total amount of hair of the boys in the neighbouring class is 154. I think that the boy with longest hair would be Cole. S and the boy with the shortest hair would be Fred (I'm not sure who Ethan is)
Grade 8 POTW:
ReplyDelete2cm, 2cm, 4cm, 4cm, 4cm, 5cm, 5cm, 5cm, 6cm, 6cm, 7cm, 7cm, 9cm, 9cm, 14cm, 15cm, 16cm
Mode: 4, 5
Median: 6
Mean: 7.06
Range: 14
The boys in the neighbourhood would have a total of around 79.32 cm of hair.
I wonder who has the longest hair. HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM. not me (:
Correction:
DeleteI got a haircut this weekend, so I no longer have the longest hair. The longest hair would most likely be Richard.
This question was posted before you got a haircut so you would have the longest hair.
DeleteRichard has the longest hair and Fred has the shortest
ReplyDeletethe mean is
7cm + 4cm + 5cm +
5cm + 15cm + 14cm +
7cm + 16cm + 2cm +
4cm + 2cm + 9cm +
5cm + 6cm + 4cm +
6cm + 9cm
------------------- = 7.058 = 7.06
17
the mode is
5 because
2=2 times 4=2 times 5=3 times 6=2 times 7=2 times 9=2 times 14=1 time 15=1 time 16=1 time
the rang is 16-2=14
the mean with the other class is 7.06+2=9.06
there for the sum of all the kids from this class and the naboring class is 9.06 times 22 = 199.32
there for the total emount of hair in the nabouring class is 199.32-120= 79.32
i'll ask jilly and jolly
ReplyDelete1 of them is cindy
ummmm, these two people are from Mrs. Fairbarn's class(My class), not Mr. Milette's. I know this because they did my hair, but I forgot who one of them was, and I'm not allowed to tell, so.... good luck!
Deletethe mean is 7.058, I added all the numbers then divided it by how many numbers there are( 120/17). The median is 6, I lined up the numbers from least to greatest then found the middle. The mode is 4 and 5, both repeat 3 times in the data. The range is 14, 16 - 2.
ReplyDeletepart two:
mean = 7.058. 7.058 + 2 = 9.058
amount of boys = 17. 17 + 5 = 22
9.058*22 = 199.276
now I subtract the length of the original class by the neighbor class.
199.276 - 120 = 79.276
therefore the total length of hair for the neighbor class is 79.276
longest hair is derek, and shortest hair is fred; at least that's what I think.
I think jilly and jolly are two boys from ms.fairbarn's class because it said the question is not for ms.fairbarn's class to answer, and because jilly and jolly are names for boys so I assume it would be the same for the actual people. so in conclusion,(based of my terrible guessing skills)
I think jilly and jolly are stanley and ethan(don't judge my guessing skills, I don't have much background knowledge when it comes to potw)
are you just guessing or do you have reasoning for who jilly and jolly are?
DeleteHe's guessing XDDDD
DeleteI don't want to be certain about my answer on jilly and joly because I can't back it up with math or anything for that matter
DeletePOTW
ReplyDeleteFirst we must find the central tendencies of the centimetres of hair of boys in Jilly and Jolly's class.
Mean= 7.058 cm
Mode= 4 & 5 cm
Median= 6 cm
Range= 14 cm
Now, we have to find the total amount of hair of the neighbouring class. To find this, we first need to know that there are 17 boys in the neighbouring class. As well, the other mean for Jilly and Jolly's class was 7.058, so by raising the mean 2 cm, the mean would now be 9.058.
First, let's figure out the total amount of boys. If the class before had 17 boys and five boys are going to lift the mean for THIS class, then we simply add those two numbers together, which would equal to 22. Now we multiply the current mean (9.058) by 22 (the number of boys) which equals to 199.276. And lastly, subtract the total length of the previous class by this class which would be 79.276. Thus meaning that this is the total length of hair for the neighbouring class. Let's recap:
7.058+2= 9.058
17+5= 22
9.058*22= 199.276
199.276-120= 79.276
The next two question are more logical then mathematical. Based on what I've seen, I believe Fred as the shortest length, and Maxwell or Cole as the longest.
As for Jilly and Jolly, like everyone else I do believe they are boys, although I was still a bit stumped on this question. I think Stanley could most definitely be one of them (knowing Stanley), but the second one I couldn't think of. My guess is Fred, just because he likes math, but I'm most probably wrong.
POTW #5
ReplyDeleteSince the problem is pretty long I broke it down into what it is asking me:
- Mean, median, mode, range
- The total of hair in the neighboring class that will make the mean go up by 2 cm with 5 people
- The longest hair
- The shortest hair
- BONUS: Who are Jilly and Jolly?
Mean, Median, Mode, Range:
Mean is 7.058. I added the numbers and divided by 17.
Median is 6. I arranged the numbers from least to greatest and found the middle number.
Mode is 4 and 5. They both occur the same amount of times.
Range is 14. The greatest number minus the smallest number.
I know that the goal is to have a mean of 9.058 since that is more than 7.058 by 2. And the number of people you divide the sum by must not be 22 instead of 17 since you need to add another 5 people. 9.058x22 is 199.276. Then, I need to subtract the previous amount, which was 120, which is 199.276 - 120 = 79.276. Therefore, the total amount of hair in the other class is 79.276.
To find the shortest and the longest hair, you much know most of your peers. From what I know, I think that the shortest hair would be Fred. The longest hair is a bit harder. I would say that it is either Maxwell, Cole S., or Richard.
For the BONUS, I know that the Jilly and Jolly must be from Mrs. Fairbarn's class since it states that students from that class may not answer it. I also think that they were probably girls since a boy would:
1. Not be as interested in hair lengths
2. Might find the question too easy since they know the hair of the same gender bit better.
I think that it may have been Ruby and Faustina. From background knowledge, i know that they can get bored extremely easily and will get WAY off task most of the time. I wouldn't be surprised if they managed to team up and make this POTW question.
Grade 7/8 POTW #5:
ReplyDeletea) Finding the central tendencies
Mean: 7.058
(7 + 4 + 5 + 5 + 15 + 14 + 7 + 16 + 2 + 4 + 2 + 9 + 5 + 6 + 4 + 6 + 9) / 17 = 7.058
Median: 6
2 , 2 , 4 , 4 , 4 , 5 , 5 , 5 , 6 , 6 , 7 , 7 , 9 , 9 , 14 , 15 , 16
The first 6 in the middle is the median.
Mode: 4 and 5
2 , 2 , 4 , 4 , 4 , 5 , 5 , 5 , 6 , 6 , 7 , 7 , 9 , 9 , 14 , 15 , 16
Both 4 and 5 appear three times.
b) They predict that the 5 boys in that class will lift the mean by 2 cm. What is the total amount of hair the boys in the neighboring class have?
Since the question specified that after adding the hair length of the 5 boys from the neighboring class, the mean will go up by 2, we must add 2 to the current mean in order to find out the new mean.
7.058 + 2 = 9.058
Now, to find out the total lengths of hair from both classes.
For people that may be confused, look at it as algebra.
x / 22 = 9.058
Solve for x. You multiply both sides by 22 and x = 199.276
The question is not asking for the total amount of hair. It is asking for the total amount of the neighboring class' hair. Previously while trying to find the mean in part a, we added all the hair lengths together and got 120.
199.276 - 120 = 79.276
Therefore, the total amount of hair from the neighboring class is 79.276.
Addition:
c) Who do you think had the longest hair? The shortest?
I predict that either Maxwell, Derek, or Richard has the longest hair out of the boys in the chart. Though, Maxwell recently got a haircut, ruling him out. As for shortest hair, I picked out Alan and Fred. Their hairstyles are very similar.
Hahaha, it's funny to watch people as they try to guess who Jilly and Jolly are. I can't wait to see their reactions when they find out. Good luck!
Sadly, I found out who it is after someone told me. I think the main reason why I got it wrong was because my finite facts weren't correct.
Delete- That gives a hint that my answer was wrong.
I hope that my hair is not the shortest. If it was then I would be very sed.
DeleteGrade 7/8 POTW:
ReplyDeleteWhat I need to find:
- Mean
- Mode
- Range
- Total amount of hair lengths in neighboring class.
Mean= The mean is around 7 because if you add up all of the data and divide by 17 (number of numbers).
Mode: The mode is 4 and 5 because they both appear twice.
Range: The range is 14 because the smallest number subtracted from the largest number is 14.
To find the sum of the hair lengths in the next class, I need to know the sum of everyone's hair length. To find the sum, I need to find out the new mean. 7+2=9. The new mean is 9. To find the total sum, I need to multiply the new mean by 22 (17+5, which is the total number of students) which gives me 198. Then, I need to subtract the old sum from the new sum. 198-120= 78. The hair lengths of the next class has to add up to 78.
I'm pretty sure that Maxwell or Richard has the longest hair (I don't care if you got a haircut). The shortest hair is probably Fred.
Grade 7/8 POTW:
ReplyDeleteMax has the longest hair and Fred has the shortest hair.
Mean:
7 + 4 + 5 + 5 + 15 + 14 + 7 + 16 + 2 + 4 + 2 + 9 + 5 + 6 + 4 + 6 + 9 = 120
120 / 17 = 7.058
The mean hair length is 7.058.
Mode: The mode is 4 and 5
Median:
2, 2, 4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 9, 9, 14, 15, 16
The median is 6.
Range: 16 - 2 = 14
The range is 14.
I think Jilly and Jolly are Mr. Milette and Mrs. Fairbarn because I don't remember any student doing this
Avi. One of the Ms. Fairbarn's students made it.
DeleteDon't you mean Avi, not Avi.
DeleteFirst, to find the central tendencies, I will line up the set of data from least to greatest, which will at least give me a hint about the median.
ReplyDelete2, 2, 4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 9, 9, 14, 15, 16
From this, I can easily tell that the first six is the median.
The next step, for me, is finding out the mean. The formula is adding all the numbers together, which is 120, and then dividing by the amount of numbers, which, in this case, is 17.
Therefore, the mean is around 7, and to be more specific, it is 7.058.
To find out the range, I subtracted 2 from 16, as 16 was the longest boy's hair, and 2 was the shortest. The answer was 14, so as a result, the range is 14.
Finally, the mode is 4 and 5, because both numbers have an equal amount of each, which is 3, more than any other number presented in the data set.
The question next asks to find out the hair length in the next class. I do know that it increases the mean by 2, so I will add 2 to the mean to make the new mean, which is 9.058. What I also know is that there are 17 boys in this class, and they are adding 5 other boys. So 17 + 5 = 22, which is the new amount of boys.
I also need to find the total sum, so to do that, I will multiply 22 by 9.058, which results in 199.276. What I have to do next is subtract the previous number, which is the total of all the numbers combined of the first set of data, which is 120. Therefore, the total amount of hair in the other class is 79.276.
For the question asking about who has the longest hair and who has the shortest hair, I assume that Derek or Richard has the longest hair, or maybe Maxwell, because I think he had a haircut after the survey was conducted, not before. For someone with the shortest hair, I guess Fred, or maybe even Alan, as they have similar haircuts, but Fred seems to have shorter hair. I'm not sure, though.
Mean: 7cm + 4cm + 5cm + 5cm + 15cm + 14cm + 7cm + 16cm + 2cm + 4cm + 2cm + 9cm + 5cm + 6cm + 4cm + 6cm + 9cm / 17
ReplyDelete= Around 7
The new mean should be 9 because 7 + 2 = 9.
9 x 22 = 198
198 - 120 = 78
Median: 2 2 4 4 4 5 5 5 6 6 7 7 8 8 14 15 16
Median = 6
Mode = 4 and 5
Range: 16 - 2 = 14.
I think that Fred has the shortest hair, and Maxwell has the longest hair.
Maxwell for longest
ReplyDeleteFred for shortest
Mean: 157/17 = 9.23
Median: 6 cm
Mode: 4 and 5 cm
Range: 16-2=14cm
9.23+2=11.23
x/22 =11.23
Now, to find out the total lengths of hair from both classes.
For people that may be confused, look at it as algebra.
x / 22 = 9.058
Solve for x. You multiply both sides by 22 and x = 199.276
199.276 - 120 = 79.276
The total amount of hair from the neighboring class is 79.276.
(((((((((((((((7 + 4 )+ 5 )+ 5 )+ 15 )+ 14 )+ 7 )+ 16 )+ 2 )+ 4 )+2 )+ 9)+ 5)+ 6)+ 4)+ 6)+ 9 = 120
ReplyDelete120/17=7.0588235294118
L:2 H:16 16-2=14
Mean: 7.0588235294118
Mode: 4 & 5
Range: 14
You can’t tell because it said predicted but did not confirm that it did raise the average.
I think the longest hair is from either Maxwell or Cole. s. I think the shortest is from Mateo or Ryan.
Ext: Michelle and Ella.
Richard had the longest hair and Fred had the shortest.
ReplyDeleteMean: (7+4+5+5+15+14+7+16+2+4+2+9+5+6+4+6+9)/17= 7.06
Median: 2 2 4 4 4 5 5 5 6 6 7 7 9 9 14 15 16 The Median is 6
Mode: The mode is 4 and 5
Range: 16-2=14 the range is 14cm
The amount of hair in the other class should be about 199.32 since 5 people have been added to the mean that becomes x(which the total amount of hair)/22=9.06 and multiplying both sides by 22 we get X=199.32 and since there's already 120 cm of hair there would be about 79.32 cm of hair from the boys assuming the estimation is correct.
Jilly and Jolly are Yoav and Ethan since this is most likely done by a pair of friends that hang out a lot (like me and Richard) and when I think of someone getting bored enough to create this I think Yoav and since Yoav hangs around Ethan pretty often I think it's Yoav and Ethan
Grade 7/8 POTW
ReplyDeleteMean:
7cm + 4cm + 5cm + 5cm + 15cm + 14cm + 7cm + 16cm + 2cm + 4cm + 2cm + 9cm + 5cm + 6cm + 4cm + 6cm + 9cm = 120 ÷ 17 = About 7.0588
7.0588 is the mean.
Median:
2cm, 2cm, 4cm, 4cm, 4cm, 5cm, 5cm, 5cm, 6cm, 6cm, 7cm, 7cm, 9cm, 9cm, 14cm, 15cm, 16cm
6cm is the median.
Mode:
4cm, 4cm, 4cm, 5cm, 5cm, 5cm
Both 4cm and 5cm are the mode
Range:
16cm - 2cm = 14cm
The range is 14cm
Knowing the Mean is about 7, Jilly and Jolly want think the next 5 measurments (22 measurements) from the other class will bring the mean up to 9
From here I can work backward to find the last numbers of the mean.
9 x 22 = 199
199 - 120 (the sum of the original data set) = 79
The next class' total will sum up to about 79cm.
I would assume Derek has the longest hair and Fred has the shortest.
For the Jilly and Jolly question, I can't really answer it because I know who it is, but it is fun seeing everyone guess. xd
To solve this problem, you first need to add all the hair lengths together. (7+4+5+5+15+14+7+16+2+4+2+9+5+6+4+6+9)=120. You then must divide by 17 (The number of people).
ReplyDeleteMean: About 7.06cm
Median: 6cm
Mode: 4 and 5cm
Range: 16-2=14cm
There was no confirmation that the average WAS raised so I cannot answer, but it would be about 72.
I think Jilly and Jolly were Ella and Michelle
Aleks=Longest Alan=Shortest
POTW 5
ReplyDelete7 + 4 + 5 + 5 + 15 + 14+ 7+ 16 + 2 + 4+ 2+ 9 + 5 + 6 + 4 + 6 + 9 = 120
120 / 17 = 7.058
The mean is 7.058
2, 2, 4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 9, 9, 14, 15, 16
Middle number is 6
The median is 6
The numbers that appear the most are 4 and 5 (they each appear three times)
The modes are 4 and 5
16 - 2 = 14
The range is 14
7.058 + 2 = 9.058 <-- This is what the mean is supposed to be
17 + 5 = 22 <-- This is how many boys in total (from both classes)
9.058 * 22 = 199.276 <-- This is the total cm of hair from BOTH classes
199.276 - 120 = 79.276 <-- This is the total cm of hair from the other class
The total amount of hair from 5 boys in the neighboring class is 79.276 cm.
I think Fred has the shortest hair. And for the longest hair, I think it would be Maxwell, Derek, or Cole S.
Grade 7/8 POTW
ReplyDeleteThe mean is about 7cm, the median is 6cm, there are two modes (4cm and 5cm), and the range is 14cm. If the mean is increased by 2, this means that each boy has an average of 9cm of hair (7+2), and since 9x5 is 45, the 5 boys have a total of 45cm of hair.
For the other question, I think that Fred or Ethan has the shortest hair, and that either Derek or Richard has the longest hair
Mean - 7. 06
ReplyDeleteMedian - 6 cm
Mode - 4 and 5
My guess is Cindy and Sevitha, work hardcopy
Derek has the longest hair, Alan has the shortest
ReplyDeleteGrade 7/8 POTW:
ReplyDelete7cm, 4cm, 5cm
5cm, 15cm, 14cm
7cm, 16cm, 2cm,
4cm, 2cm, 9cm,
5cm, 6cm, 4cm,
6cm, 9cm
Mean:
7+4+5+5+15+14+7+16+2+4+2+9+5+6+4+6+9=120
120 / 17 = about 7cm
7cm
Mode: 4 and 5 are repeated the most
4cm and 4cm
Range: 16-2=14
14cm
Here is how I went about solving the Grade 7/8 POTW:
ReplyDeleteMaxwell would have the longest hair and Fred would have the shortest hair.
Mean:
7 + 4 + 5 + 5 + 15 + 14 + 7 + 16 + 2 + 4 + 2 + 9 + 5 + 6 + 4 + 6 + 9 = 120
120 / 17 = 7.058
The mean hair length is 7.058.
Mode: The mode is 4cm and 5cm
Median:
2, 2, 4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 9, 9, 14, 15, 16
The median would be 6.
Range: 16 - 2 = 14
The range would be 14.
POTW #5:
ReplyDeleteMean: We have to add up all of the values in the sequence to find the sum to divide the amount of values in the sequence to get the mean.
7cm + 4cm + 5cm + 5cm + 15cm + 14cm + 7cm + 16cm + 2cm + 4cm + 2cm + 9cm + 5cm + 6cm + 4cm + 6cm + 9cm
= 120
120/17
= 7.058
The mean is 7.058
Mode: We have to find the most repeated number to find the mode.
2, 2, 4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 9, 9, 14, 15, 16
The most repeated numbers are 4 and 5.
The mode in the sequence are: 4 and 5
Median: To find the median,you have to find the middle number of the sequence in order;
2, 2, 4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 9, 9, 14, 15, 16
In this case the middle number (Median) is 6
The median is 6
Range: The range is the greatest number subtract the lowest.
16 - 2 = 14
Therefore, 14 is the range.
The range in this sequence is 14.
To find the new mean, You have to add 2 to the existing mean.
7.058 + 2 = 9.058
Then. you will have a sum that can be divided by 9.058 and has 22 numbers in the sequence. Why 22? It's because that 5 people have their hair up. So we have to multiply 9.058 by 22 because we have to work backwards with algebra.
9.058 x 22 = 199.276
Now, We have to subtract 199.276 to 120 (The last value that gave us 7) to get the sum of the hair length in the other class.
The sum of the hair length in the other class is 79.276.
I don't actually know who's hair length is the longest and who's is the shortest. I don't really pay attention to hair...
Mean = 7
ReplyDeleteMedian = 6
Mode = 4 and 5
Range - 14
New mean should be 9 (7+2=9).
9 x 22 = 198
198 - 120 = 78
Total amount of hair = 78cm
Max has longest, Yoav has shortest
Grade 7/8 POTW #5
ReplyDelete2, 2, 4, 4, 4, 5, 5, 6, 7, 7, 9, 9, 14, 15, 16
2 + 2 + 4 + 4 + 4 + 5 + 5 + 6 + 7 + 7 + 9 + 9 + 14 + 15 + 16= 109
16-2=14
109/15 = 7.26
The mode is 4
The mean is 7.26
The range is 14
For the mean to be raised by 2 the sum of all the numbers will have to be 185.2. I know this because I multiplied 9.26 (the mean raised by 2) by 20 (the amount of boys’ hair measured) I got 185.2. 185.2 is 76.2 cm more than the original sum of all the boys hair. That means the 5 other boys hair length had the sum of 76.2. The sum of the boys in the neighboring class’ hair length is 76.2 cm
I think that Ethan has the shortest hair and Max or Derek have the longest hair.
whoops the mode is also 5
ReplyDeleteMean: 7
ReplyDeleteMode: 4
For the mean to be raised by to sum of the hair lengths in the other class would have to be 185.
Mean: 7.058
ReplyDeleteMedian: 6
Mode: 5,4
Range:14
IN order for the mean to increase by 2 (with the other classes hair lengths) The other hair lengths would have to be ,17, 18, 19, 20, 18 in order for the mean (average) to be 9.
I feel Cole.S would have the longest hair and Fred would have the shortest