+6 Can someone explain to me what D below is asking? I know how to find the answers to A, B, C and E, but have NO idea what to do for D!
Thanks so much for any help or guidance.
Given the sample data.
x: 16 21 23 30 22
Questions:
A. Find the Range
my answer: 14
B. Verify that Σx = 112 and Σx2 = 2610
C. Use the results of part (b) and appropriate computation formulas to compute the sample variance s2 and sample standard deviation s.
s2: 25.3
s: 5.0
D. Use the defining formulas to compute the sample variance s2 and sample standard deviation s.
s2:
s:
E. Suppose the given data comprise the entire population of all x values. Compute the population variance σ2 and population standard deviation σ.
σ2: 20.2
σ: 4.4
How did you calculate c) part?
I believe it's supposed to go like this:
\(DX = EX^2 - (EX)^2 = \frac{1}{5}2610 - (\frac{1}{5}112)^2=20.24\)
And for d) you would use formula:
\(\frac{1}{n} \sum_{i=1}^n (X_i - X_m)^2\)
where \(X_m = \frac{1}{n}\sum X_i\)
In your case: \(\frac{1}{5} (6.4^2 + 1.4^2 + 0.6^2 + 7.6^2 + 0.4^2) = 20.24\)
So, same stuff, just using different technique.
Cheers.
