A machine is set to fill the small-size packages of Smarties candies with 56 candies per bag. A sample revealed: four bags of 56, two bags of 57, one bag of 55, and two bags of 58. To test the hypothesis that the mean candies per bag is 56, how many degrees of freedom are there?
A) 9
B) 1
C) 8
D) 7

Question

Quizplus · Accepted Answer

To test the hypothesis, we use a one-sample t-test. The formula for calculating degrees of freedom for a one-sample t-test is df = n-1, where n is the sample size. In this case, there are 7 bags of Smarties candies in the sample, so the degrees of freedom are df = 7-1 = 6. However, the sample size is large enough that we can use a t-distribution instead of a normal distribution, so we can use the infinity symbol (∞) instead of a specific number for degrees of freedom. Therefore, the best choice is (C) 8, since it is the closest to the actual degrees of freedom of 6.

A Machine Is Set to Fill the Small-Size Packages of Smarties