Question

A) A look at all Ontario households using natural gas heating in 2012 shows that the mean monthly consumption of natural gas is 107.73 ft³, with a standard deviation of 13.95 ft³. For a sample of 65 households, the sample mean found was 105.65 ft³. Use this information to find the margin of error E and to construct a 93% confidence interval for the mean monthly consumption for the population of all Ontario households. Is this sample a good estimation of the population mean monthly consumption of natural gas for all Ontario households?

B) Suppose that we have only 10 temperatures of people undergoing surgery, as below.

36.4     36.5     36.7     36.7     36.5     36.6     36.6     36.5     35.6     36.5

Calculate the sample mean (x with line above) and standard deviations.   

Find the margin of error E and construct the 99% confidence interval for the mean of all body temperatures (a prior study has shown that body temperatures are normally distributed).

Answer 1