Question

A cruise company would like to estimate the average beer consumption to plan its beer inventory levels on future seven-day cruises. (The ship certainly doesn't want to run out of beer in the middle of the ocean!) The average beer consumption over 14 randomly selected seven-day cruises was 81,619 bottles with a sample standard deviation of 4,521 bottles. Construct an 80% confidence interval to estimate the average beer consumption per cruise.

The 80 % confidence interval to estimate the average beer consumption per cruise is from a lower limit of ________ bottles to an upper limit of _______bottles.

Answer 1

Here given sample size(n)= 14

Sample mean()=81619

Sample standard deviation (s) = 4521

here population standard deviation is not known

so, we have to use the t-tables to write the critical value ( )

at 80% confidence = 1.3502

The 80% confidence intervals is

=

=

=

=

At 80% confidence the average beer consumption per cruise is from a lower limit of 79987.57 bottles

to an upper limit of 83250.43 bottles