Question

Will Medal!!

What is the first quartile (Q1) of the data set?

48, 40, 59, 74, 51, 45, 62, 69



A. 74


B. 65.5


C. 46.5


D. 40

Answer 1

First arrange it into ascending form

Answer 2

okay,

40, 45, 48, 51, 59, 62, 69, 74

Answer 3

okay now for the first quartile find the (8+1)/4 position
which is 2.75th position. So find the average of 2nd and 3rd number

Answer 4

okay it's 46.5 right?

Answer 5

Think: Could 46.5 be the average of 51 and 59?

Answer 6

If not, find the mean (average) of 51 and 59 (which are the two middle numbers).

Answer 7

the first person who replied said the 2nd and 3rd numbers he didn't give a specific number so i did45 and 48

Answer 8

so the average of those would be... 55?

Answer 9

Unfortunately you cannot accept what you are told without first checking it out yourself. You have arranged your data correctly, in ascending order.

Which are the 2 middle numbers of your data set?

What is their average?

Answer 10

Yes, the median of the whole set is 55. That's better.

Now, go back and re-read the problem statement. What are you to find?

Answer 11

I'm so sorry but, I'm not entirely sure.

Answer 12

it says what the quartile of the "data set" is.

Answer 13

"What is the first quartile (Q1) of the data set? "

Your data set has an even number of elements.

Half of the data is on the left of the median (55) and half is on the right of the median.

Question for you: What does "first quartile" mean, and how do you find it?

Answer 14

I don't want to put frustration on you at all but, I'm not sure how to do this very well. and thank you so much for helping me through this slowly :)

Answer 15

A quick summary:

The "median" of a data set of n elements is the middle element, if n is odd; if n is even, the "median" of the set is the average of the two middle elements. That's how you got the median 55 of the whole data set.

The "first quartile" is the median of the left half of the data set. In your case that "left half of the data set" would be 40, 45, 48, 51.

Using the definition I've given you, find the median of 40, 45, 48, 51. To do this, find the mean of 45 and 48.

Answer 16

I said that before it's 46.5

Answer 17

that's the mean of 45 and 48

Answer 18

so the answer's C!