Question

While population mean is claimed to be 20, does observing a sample average of 25 with a sample standard deviation of 4 from 11 samples imply that the population mean may not be 20? (there is no additional info for this question you can use whatever method you can like)

Answer 1

Given : Sample size=n=11

Sample mean=

Sample standard deviation=s=4

Hypothesized value=

Assume that the significance level=

1) Hypothesis : Vs  

2) The critical values ar e,

; From t-table

3) The test statistic is ,

4) Decision : Here , the value of the test statistic lies in the rejection region.

Therefore , reject Ho.

5) COnclusion : Hence , there is not sufficient evidence to support the claim that the population is mean is to be 20.