In: Statistics and Probability
Describe the following sampling distributions. What are the means and standard errors, and are we guaranteed of normality?
a. μ = 20; σ = 4; n = 64
b. P = 70%; n = 30
a)
Solution :
Given that,
mean =
= 20
standard deviation =
= 4
n = 64
The sampling distribution of mean is ,
= 20
The sampling distribution of standard deviation is ,
=
/
n = 4/
65
= 0.4961
b)
Solution
Given that,
p = 70 % = 0.70
1 - p = 1 - 0.70 = 0.3
n = 30
The mean of the sampling distribution of proportion is ,
= p = 0.70
The standard error of the sampling distribution is ,
=
[p(
1 - p ) / n =
[0.70 (0.3) / 30] = 0.0837
= 0.0837