Answer:
The 99% confidence interval would be given by (0.286;0.562)
Step-by-step explanation:
Information given:
represent the families owned at least one DVD player
represent the total number of families
represent the estimated proportion of families owned at least one DVD player
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by and
. And the critical value would be given by:
The confidence interval for the mean is given by the following formula:
If we replace the values obtained we got:
The 99% confidence interval would be given by (0.286;0.562)