Question

A simple random sample of 64 observations was taken from a large population. The sample mean and the standard deviation were determined to be 320 and 120 respectively. The standard error of the mean is:________

a. 1.875
b. 40
c. 5
d. 15
e. None of the above

Answer 1

The correct option is d

Explanation:

From the question we are told that

The sample size is n = 64

The mean is
`\= x = 320`

The standard deviation is
`\sigma = 120`

Generally the standard error of the mean is mathematically represented as

`\sigma_x = (\sigma)/( √(n) )`

=>
`\sigma_x = (120)/( √(64) )`

=>
`\sigma_x =15`