You are given the sample mean and the population standard deviation. Use this information to construct a 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals.

From a random sample of 48 business days from January 4, 2010 through February 24, 2017, U.S. gold prices had a mean of $1368.48. Assume the population standard deviation is $202.60.

=Answer

=Answer

n =Answer

Part 1: 90% confidence interval

zc=Answer

E =Answer

Round E to the nearest thousandth.

C.I. = (Answer

,Answer

)Round C.I. to the nearest hundredth.

Part 2: 95% confidence interval

zc=Answer

E =Answer

Round E to the nearest thousandth.

C.I. = (Answer

,Answer

)Round C.I. to the nearest hundredth.

Part 3: Compare the widths of the confidence intervals.

The 95% confidence interval isAnswer

wider

narrower

than the 90% confidence interval.

Part 4: Does it seem possible that the population mean could equal the sample mean?

Answer

Yes

No