Question

pls help me wil give medal For the data shown in the stem-and-leaf plot, what is the effect on the mean and median of adding the value 30 to the data set?



A.
The mean is increased by about 0.4 and the median is increased by 3.

B.
The mean is increased by about 0.4 and the median is increased by 4.

C.
The mean is increased by about 0.6 and the median is increased by 3.

D.
The mean is increased by about 0.6 and the median is increased by 4.

Answer 1

find the mean of just the data given in the picture you posted, what do you get?

Answer 2

i dont understand this i never done this before

Answer 3

no problem, i'll show you ^_^

Answer 4

the first row becomes the numbers: 6 and 8
the 2nd row becomes the numbers: 12, 15, 18
3rd row: 20, 20, 20, 26, 28, 29
4th row :30, 31, 32, 32, 34

got it?

Answer 5

yes

Answer 6

^_^


now to find the the median I count in from both sides,
so 6 and 34 are paired
8 and 32 are paired
12 and 32 are paired
15 and 31 are paired,
keep couting in until you are at the same number, what do you get?

Answer 7

18 wil be paired with 26? @DemolisionWolf

Answer 8

close!
so here are the number in order:
6, 8, 12, 15, 18, 20, 20, 20, 26, 28, 29, 30, 31, 32, 32, 34

if I count in 8 numbers from the left I'm at 20
if I count in 8 numbers from the right im at 26

do you see it?

Answer 9

yes

Answer 10

great, so to get the median, we take these two numbers, 20 and 26, add them together.

then divide by 2, what do you get? (this will be the median value)

Answer 11

thats 23 @DemolisionWolf

Answer 12

correct ^_^
so that is the meadian of the numbers!

Answer 13

now, if we have
6, 8, 12, 15, 18, 20, 20, 20, 26, 28, 29, 30, 31, 32, 32, 34

and I add in a 30, so
6, 8, 12, 15, 18, 20, 20, 20, 26, 28, 29, 30, 30, 31, 32, 32, 34

what is the median now?
hint: count in 9 numbers from both sides

Answer 14

i counted and i got 6 and 34 and i added them to together and i got 40 do i divide if i do with what number ? @DemolisionWolf

Answer 15

so, when we 'count in from both sides'

its like this:

counting in 9 from the left side
1 2 3 4 5 6 7 8 9
6, 8, 12, 15, 18, 20, 20, 20, 26,

see how 26 is the 9th number?

now you count in from the right side 9 numbers, what do you get?

Answer 16

6?

Answer 17

not quite
6 is the first number on the left..

what is the number on the farthest right of:
6, 8, 12, 15, 18, 20, 20, 20, 26, 28, 29, 30, 30, 31, 32, 32, 34

Answer 18

34

Answer 19

right
then the second number in from the right would be?

Answer 20

32 @DemolisionWolf

Answer 21

right, good, so you get how to count in from the right,.

so keep going right to left and from 34, count in 9 numbers

Answer 22

good job today, i gotta go now, there are lots of others on here that can help you the rest of the way

Answer 23

ok thank you