About Lesson
Sampling distribution of mean
Describes possible outcomes i.e. mean or mode of some variables.
When the population is normally distributed, then
a) Shape is normally distributed
b) Same size doesn’t affect the center of distribution
Sampling distribution depends on:
a) Sampling procedure
b) Statistics
c) Use of sample size
mathematically,
Sample size ( n) = Z2Pq/d2
Where,
n = sample size
z = 1.96
p = 0.5
q = 1-p
d = 0.05 ( Absolute precision or accuracy)
Note:
a. Spread or standard error:
SE =σ/ √n where, σ = Standard deviation and n = no. of sample.
b. Standardizing a sample mean ( Standard Normal distribution)
Standardized sample mean (z) = x-µ/ σ
Where, z = standard score, x= observed value , µ = mean of the sample and σ = standard deviation of the sample
