I need help with this exercise.
The US Census Bureau conducts the Current Population Survey each year in its states and territories. The following table comes from the Census page and describes the average family income in a certain state.
a) Find a 90% confidence interval for the means of family income in that state between the years 2021 and 2020.
The instructions aren't clear for me. Is this a confidence interval for one mean for each year? or is this a confidence interval for the difference of the means? In past test prof. evaluate the confidence interval for 1 mean and right now we are suppose to be working with two. But either way I don't have here the size of the samples and they are in the formulas.
And then my other question is, since this is a survey these are statistics right? Those average and standard deviation are from the samples? So it must be used t-student distribution to find the critical value?
b) Could you conclude that the average family income in Puerto Rico increased significantly? Justify.
This is an hypothesis test for the difference of the means? Also, to find the test statistic I need the sample sizes and they are not provided. :-/