Test of a Single Variance · Exercise 27

For each word problem, use a solution sheet to solve the hypothesis test problem. Go to for the chi-square solution sheet. Round expected frequency to two decimal places.

The number of births per woman in China is 1.6, down from 5.91 in 1966. This fertility rate has been attributed to the law passed in 1979 restricting births to one per woman. Suppose that a group of students studied whether the standard deviation of births per woman was greater than 0.75. They asked 50 women across China the number of births they had. The results are shown in. Does the students’ survey indicate that the standard deviation is greater than 0.75?

\begin{array}{|c|c|}\hline \text{# of Births} & \text{Frequency} \\ \hline \text{0} & \text{5} \\ \hline \text{1} & \text{30} \\ \hline \text{2} & \text{10} \\ \hline \text{3} & \text{5} \\ \hline\end{array}

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Statistics · §11.6 Test of a Single Variance · Exercise 27