Question

Help !
The back-to-back stem-and-leaf plot below show exam scores from two different math classes. Which class has a greater mean score? Which class has a greater median score?

Answer 1

ANSWERS :

A. greater mean = class A greater median = class A
B. greater mean = class B greater median = class B
C. greater mean = class B greater median = class A
D. greater mean = class A greater median = class B

Answer 2

Looking at row 1, class A has the values: 41 and 45. Also in row 1, class B has the value 42

In row 2, class A has: 51, 56, 58 and class B has 54

Do you see how I'm getting these values?

You basically extract all the values from each class and you find the mean value of each class

Answer 3

oh okay i kind of get it but i dont get the answers above they really dont makke sense to me

Answer 4

choice A says "class A has the greater mean and class A has the greater median"

the rest of the choices are along the same lines

Answer 5

so you need to find the mean and median of each group

Answer 6

i tried but i marked answer c and it was wrong ....

Answer 7

did you manage to write down all the values that lie in class A? and all the values that lie in class B?

Answer 8

i believe so ..

Answer 9

Did you get

41,45
51,56,58
65,67,67,69
76,76,77,78,79
81,82
91

for class A

----------------------

and

42
54
61,66
72,75,76,76
80,80,84,88,89
93,95,96,97

for class B

??

Answer 10

no !

Answer 11

alright find the mean and median of each and tell me what you get

Answer 12

for each line or the whole class?

Answer 13

the whole class

Answer 14

do class A and B separately

Answer 15

okay ! hold on let me try it quick !

Answer 16

alright

Answer 17

mean for class a is 68.17 rounded to 68.2 mean for class b is 77.88 round to 77.9
median for class a is 69 . median for class b is 80 !

Answer 18

you are correct on all 4 items

Answer 19

so class B has the greater mean and median

Answer 20

yay (: but i dont get the answers !

Answer 21

what part doesn't make sense

Answer 22

like i dont gget how to put it into that equation ... can you like explain because i still dont know the answer because i dont get it

Answer 23

to find the median, you sort the values from smallest to biggest, then you pick out the middle most value

to find the mean, you add up all the values, then you divide by n

Note: n = number of values

Answer 24

There's no real formula for the median (since it's something that takes a sentence or two to explain how to find). The mean can be represented by the formula

mean = \(\Large \frac{\sum x_{i}}{n}\)

but that probably complicates things (a bit)

Answer 25

yea i really dont get that ..

Answer 26

so would it be b ?

Answer 27

yes it would be choice B since class B has a greater mean and greater median

Answer 28

If possible, ask your teacher about finding the mean and median (and about stem and leaf plots) if you're still confused about this. S/he may provide a more clear explanation. Of course, you can ask me or anyone on here as well.

Answer 29

thank you so much ! (: