Use One-Proportion Z-Test
12.56 Christmas Presents. The Arizona Republic conducted a telephone poll of 758 Arizona adults who celebrate Christmas. The question asked was, "In your family, do you open presents on Christmas Eve or Christmas Day?" Of those surveyed, 394 said they wait until Christmas Day.
a. Determine the sample proportion.
b. At the 5% significance level, do the data provide sufficient evidence to conclude that a majority of Arizona families who celebrate Christmas wait until Christmas Day to open their presents?
12.58 Families in Poverty. In 2000, 8.6% of all U.S. families had incomes below the poverty level, as reported by the U.S. Census Bureau in Current Population Reports. During that same year, of 400 randomly selected families whose householder had at least a Bachelor's degree, 9 had incomes below the poverty level. Do the data provide sufficient evidence to conclude that in 2000, the percentage of families that earned incomes below the poverty level was lower among those whose householders had at least a Bachelor's degree than among all U.S. Families? Use a=0.01.
The solution provides step by step method for the calculation of testing of hypothesis. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.