An experiment was performed on a certain metal to determine if the strength is a
function of heating time. The 95 percent confidence interval for the average strength of
a metal sheet when the average heating time is 4 minutes is from 4.325 to 5.675.
Therefore, we are confident at α = .05 that the average strength of this metal heated for
four minutes is between 4.325 and 5.675 pounds per square inch. Do you agree or
disagree with this statement?
Consider a set of 50 measurements with mean 50.2 and standard deviation 18.7 and
with the following observed and expected frequencies.
It is desired to test whether these measurements came from a normal population.
Calculate the value of the chi-square test statistic.