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MA 121 (Intro to Stats) issues with section 8 practice question


#1

For the question listed below, I keep arriving at ‘8.7’ after calculating. According to Saylor, the answer should be ‘7.97’. I don’t see how I am wrong. Can anyone offer any insight?

What is the 25th percentile of Y based on “Definition 3”?
7.64
8.86
7.62
11.04
10.97
7.37
8.57
10.93
10.87
13.31
8.70
10.41
12.88
7.34
8.37
9.85
10.66
9.96
8.42
12.87
10.63
6.93
10.47
10.73
10.93
12.68
12.07
9.37
12.17
7.26
6.24
9.38
12.15
10.05
11.19
12.04
11.03
7.97
4.43
8.73
11.99
7.81
7.93


#2

I also get 8. Could there be a mistake? You can also ask at write my thesis website. They usually know everything.


#3

I don’t know what “Definition 3” says, but the standard meaning of percentile is this:
A percentile is a measure used in statistics indicating the value below which a given percentage of observations in a group of observations fall. See https://en.wikipedia.org/wiki/Percentile

10/43 = 0.232…
11/43 = 0.255…

There are 43 numbers. Ordered from smallest to largest, with smallest at the bottom, the 10th one from the bottom is less than 25% of the way up the column, and the 11th one is more than 25% of the way up the column. So 25% of the scores can be found below 7.97.