Let the following sample of 8 observations be drawn from a
normal population with unknown mean and standard deviation: 28, 23,
18, 15, 16, 5, 21, 13.
a, Calculate the sample mean and the sample standard
deviation. (Round intermediate calculations to at
least 4 decimal places. Round "Sample mean" to 3 decimal places and
"Sample standard deviation" to 2 decimal places.)
Sample mean
Sample standard
deviation
b, Construct the 90% confidence interval for the population
mean. (Round "t" value to 3 decimal places
and final answers to 2 decimal places.)
Confidence interval
to
c, Construct the 95% confidence interval for the population
mean. (Round "t" value to 3 decimal places
and final answers to 2 decimal places.)
Confidence interval
to _____