Consider a situation in which Rosa measures the diameter of 15 trees from a population that she thinks (based on published reports) has an average diameter of 240 cm. Her sample has a mean of 253.1 cm with a standard deviation of 25.21 cm. Based on her t-test statistic, which of the following best describes her conclusion?

Question

Quizplus · Accepted Answer

The t-test statistic is used to test the null hypothesis that the mean of a population is equal to a specified value. In this case, the null hypothesis is that the mean diameter of the trees is equal to 240 cm. The t-test statistic is calculated as the difference between the sample mean and the hypothesized population mean, divided by the standard error of the mean. The standard error of the mean is calculated as the standard deviation of the sample divided by the square root of the sample size. In this case, the t-test statistic is calculated as (253.1 - 240) / (25.21 / sqrt(15)) = 2.14. The p-value for this t-test statistic is 0.054, which is greater than the significance level of 0.05. Therefore, we fail to reject the null hypothesis and conclude that the mean diameter of the trees doesn't seem to differ from 240 cm.

Consider a Situation in Which Rosa Measures the Diameter of 15