- #1
n77ler
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Homework Statement
The following 25 measurements were obtained on the eyes of over 100 university students.
0.04 0.06 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.09 0.10 0.11 0.12 0.12 0.15 0.16 0.16 0.16 0.17 0.17 0.17 0.20 0.21 1.07
a) Find the 10th percentile of these measurements. Interpret the result
b)Calculate the z-score for the measurement of 1.07. Interpret the result.
Homework Equations
I= (P/100)n
P defined as percentile
n defined as #of measurements
The Attempt at a Solution
I= (10/100)25 = 2.5 Round up to 3. So the 10th percentile is the third value when rearranged from smallest to greatest. It ends up being the second 0.06 value in the set. So how do I write the final answer? Do I just circle the third value?
z-score needs mean. x(bar)= sum of all numbers/ number of measurements
mean= 0.1544
z-score= (1.07-0.1544)/25 = 0.0366 but this seems a little small for a z-score doesn't it? when the number is much bigger(or the outlier) than the rest of the data?