Question

The two dot plots below compare the forearm lengths of two groups of schoolchildren:


Based on visual inspection of the dot plots, which group appears to have the longer average forearm length?

Group A, because seven children have a forearm length longer than 10 inches
Group B, because two children have a forearm length longer than 10 inches
Group A, because one child in the group has the least forearm length of 9 inches
Group B, because three children in the group have the least forearm length of 9 inches

Answer 1

Am I right with B?

Answer 2

hmm look at the numbers and how they're distributed

which one would have a larger mean?

Answer 3

B?

Answer 4

Ohh ok

Answer 5

no

if you wanted, you could even calculate the mean

group A
(10+10+10+11+11+11+11+12+12+12) / 10

group B
(9+9+9+10+10+10+10+10+11+11) / 10

Answer 6

but just by looking at the graph, you can see how group A has larger numbers so then it's mean should be ...

Answer 7

Is it 11

Answer 8

that's the mean of group A, yeah

Answer 9

What do i need to figure out now?

Answer 10

So which one has a higher mean/average?

And then think about it

Answer 11

does the mean increase by having one larger number of by having multiple larger numbers?

Answer 12

so for group B its 9.9

Answer 13

so its obviously a or c now right?

Answer 14

Am I right with C?

Answer 15

@az

Answer 16

anyone here?

Answer 17

sorry, I stepped away

you eliminated it down to A and C

but keep in mind how the mean changes

if you add one number but it's a really HUGE number, then yeah the mean will change so like if you added one number of 20

but we're looking at these numbers 10, 11, 12

Answer 18

actually just read the answer choices

A) Group A, because seven children have a forearm length longer than 10 inches
C) Group A, because one child in the group has the least forearm length of 9 inches

does Group A have anyone with a forearm length of 9?
And would even having that contribute to having a larger mean? Wouldn't it bring down the mean instead?

Answer 19

group A does not have anyone with a forearm length of 9

Answer 20

exactly so what's your answer

Answer 21

A

Answer 22

There you go

Answer 23

Okay, thank you. that took so long lol

Answer 24

Yeah sorry about that haha