Question

For the following data values below, construct a 90% confidence interval if the sample mean is known to be 0.719 and the standard deviation is 0.366. (Round to the nearest thousandth) 0.56, 0.75, 0.10, 0.95, 1.25, 0.54, 0.88

Answer 1

Formula for Confidence Interval for Population mean when population Standard deviation is not known

Sample mean : = 0.719

Sample standard deviation : s = 0.366

Sample size : Number of data values : n = 7

Degrees of freedom : n-1 = 7-1 =6

for 90% confidence level = (100-90)/100=0.10

/2 = 0.10/2 = 0.05

90% confidence interval for the population mean :

90% confidence interval (0.4502,0.9878)