Question

calculate the third quartile, Q3 for the following data

39, 9, 27, 40, 10, 11, 36, 42, 11, 8, 18

a) 22.818

b) 8

c) 39

d) 42

e) 18

- I'm doing 3(11+1/4) and keep getting 9 but that's not an answer choice.

Answer 1

Let me help you with this.

The first task is to put the data into ascending order, as shown in the table below

Position	X (Asc. Order)
1	8
2	9
3	10
4	11
5	11
6	18
7	27
8	36
9	39
10	40
11	42

For Q3​ we have to compute the following position:

Since 9 is an integer number, Q3​ is computed by locating the value that is 9th position in the table with data in ascending order, which means that in this case

OPTION C

You were calculating the position, not the quartile.

Hopefully, this clears things up!
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