Assume that 20 people participated in a speed reading class for 6 months. Each person's speed of reading words per minute both before and after the program is determined and recorded. The following summarizes the results for the 20 people: Mean weight lost = 9 pounds Sample standard deviation of weight lost = 4.6 pounds Assume that the hypothesis test will be conducted to determine whether or not the weight loss program is effective using a 0.05 level of significance. What is the value of the test statistic?
A) t = 18.634
B) t = 1.96
C) z = 1.96
D) z = 6.19

Question

Quizplus · Accepted Answer

The test statistic is calculated using the formula $t = \frac{\bar{x} - \mu}{(s/\sqrt{n})}$, where $\bar{x}$ is the sample mean, $\mu$ is the population mean (assumed to be 0 if we're testing for any change), $s$ is the sample standard deviation, and $n$ is the sample size. Plugging in the given values ($\bar{x} = 9$, $s = 4.6$, $n = 20$), we get $t = \frac{9}{(4.6/\sqrt{20})}$, which results in approximately 18.634.

Assume That 20 People Participated in a Speed Reading Class