Question

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 21 adolescents with alcohol use disorders to determine whether the hippocampal volumes in the alcoholic adolescents were less than the normal volume of 9.02 cm³. an analysis of the sample data revealed that the hippocampal volume is approximately normal with no outliers and ( \bar{x}=8.17 mathrm{~cm}^{3} ) and ( s = 0.8 mathrm{~cm}^{3} ). conduct the appropriate test at the ( alpha=0.01 ) level of significance
state the null and alternative hypotheses.
( h_{0}: mu=9.02 )
( h_{1}: mu<9.02 )
(type integers or decimals. do not round.)
identify the t - statistic
( t_{0}=square ) (round to two decimal places as needed.)

Explanation:

Step1: Recall the formula for t - statistic

The formula for the t - statistic in a one - sample t - test is \(t=\frac{\bar{x}-\mu}{s/\sqrt{n}}\)

Step2: Identify the values

We are given that \(\bar{x} = 8.17\), \(\mu=9.02\), \(s = 0.8\), and \(n = 21\)

Step3: Substitute the values into the formula

$$
LATEXBLOCK0
$$

Answer:

\(t_0=-4.87\)