Plz Help! Can you find the interquartile range of this data set??
76, 82, 73, 93, 91, 81, 79, 86, 84
I thought the answer was 11 but my teacher said it was wrong!

Question

Plz Help! Can you find the interquartile range of this data set??
76, 82, 73, 93, 91, 81, 79, 86, 84
I thought the answer was 11 but my teacher said it was wrong!

amistre64 · Answer

how did you go about getting the 11?  that way we can find the trouble area, if there is one

amistre64 · Answer

if we subtract 70 from all the data points we get:
{76, 82, 73, 93, 91, 81, 79, 86, 84}-70

6, 12, 3, 23, 21, 11, 9, 16, 14 ; which is an equivalent set

anonymous · Answer

Um I ordered the data, found the median, took out the median and then found the median of those two sets. Then I subtracted the uq from the lq.

amistre64 · Answer

sounds valid, the median of the medians ...

i tend to just go for broke:

there are 9 data points; 9/4 = 2.x, rnd to 3
                                9*3/4 = 6.x, rnd to 7

on the ordered arrangment, subtract the 7th postiion from the 3rd position

amistre64 · Answer

3,6,9,11,12,14,16,21,23
      ^                 ^

16-9 = 7

anonymous · Answer

Oh thanks!

amistre64 · Answer

most likely you just pulled off the wrong values, but the method was good