(7) A random sample of 36 college graduates revealed that they worked an average of 5...

(7) A random sample of 36 college graduates revealed that they worked an average of 5 years on the job before being promoted. The sample standard deviation is 2.0 years. Using the 95 degree of confidence, what is the confidence interval for the population mean?

Expert Solution

We have given that,

Sample mean =5
Sample standard deviation =2
Sample size =36
Level of significance=1-0.95=0.05
Degree of freedom =35

t critical value is (by using t table)=2.0301

Confidence interval formula is

=(4.32,5.68)



Lower confidence limit=   4.32

Upper confidence limit=   5.68

Therefore, 95% confidence interval for population mean is between 4.32 years to 5.68 years.

orchestra answered 2 years ago

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