In a study, researchers wanted to measure the effect of alcohol on the hippocampal region, the portion of the brain responsible for long-term memory storage, in adolescents. The researchers randomly selected 15 adolescents with alcohol use disorders to determine whether the hippocampal volumes in the alcoholic adolescents were less than the normal volume of \( 9.02 \mathrm{~cm}^{3} \). An analysis of the sample data revealed that the hippocampal volume is approximately normal with no outliers and \( \bar{x}=8.07 \mathrm{~cm}^{3} \) and \( \mathrm{s}=0.8 \mathrm{~cm}^{3} \). Conduct the appropriate test at the \( \alpha=0.01 \) level of significance. State the null and alternative hypotheses. \( \mathrm{H}_{1}: \mu \cdot \mu \) (Type integers or decimals. Do not round.)

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.52 and a standard deviation of 0.41 . Using the empirical rule, what percentage of the students have grade point averages that are greater than 3.34 ? Please do not round your answer. Answer How to enter your answer (opens in new window)

A water bottling facility has a mean bottling rate of 34.1 thousand bottles per hour with a standard deviation of 2.13 thousand bottles. A nearby cola bottling facility has a mean bottling rate of 25.7 thousand bottles per hour with a standard deviation of 1.63 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m., the water bottling facility bottled 37.2 thousand bottles of water, and the cola bottling facility bottled 27.7 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

Suppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.06 and a standard deviation of 1.52 . Using the empirical rule, what percentage of American women have shoe sizes that are greater than 9.58 ? Please do not round your answer.

The grades on the second statistics test for Mr. Brown's class are in the following list. Find the frequency distribution for the grades. \[ \text { C, D, B, F, B, A, F, F, B, B, B, F, D, B, F, D, F, B, F, B, C } \]

Find the range of the following data set. Assume the data set is a sample. \[ 43 \quad \begin{array}{lllllllll}54 & 51 & 86 & 39 & 51 & 52 & 45 & 81 & 46\end{array} 46 \]