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 \( \overline{\mathrm{x}}=8.07 \mathrm{~cm}^{3} \) 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. \( \mathrm{H}_{1}: \mu \) (Type integers or decimals. Do not round.)

A water bottling facility has a mean bottling rate of 33.5 thousand bottles per hour with a standard deviation of 1.92 thousand bottles. A nearby cola bottling facility has a mean bottling rate of 26.2 thousand bottles per hour with a standard deviation of 1.42 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m., the water bottling facility bottled 36.8 thousand bottles of water, and the cola bottling facility bottled 28.4 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

A water bottling facility has a mean bottling rate of 35.2 thousand bottles per hour with a standard deviation of 2.04 thousand bottles, A nearby cola bottling facility has a mean bottling rate of 26.9 thousand bottles per hour with a standard deviation of 1.51 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m., the water bottling facility bottled 36.9 thousand bottles of water, and the cola bottling facility bottled 27.9 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

In how many ways can a committee of 5 students be formed from 10 students?

Four scenarios of statistical studies are given below. Decide which study uses a population parameter. Answer 1000 of the 1883 participants in last year's Ironman in Kona, Hawail were interviewed. \( 68 \% \) of those interviewed said they became interested in triathlons after first ofmpeting in marathons. 351 dog owners who were surveyed, 70 reported owning two dogs. Parkland Hospital performs 15,000 births a year. Of 1000 subjects in a study on multiple births, 38 gave birth to twins. in \( 2001.78 \% \) of children diagnosed with cancer were in remission after five years, and this number is improving.

Scores on a test have a mean of 78 and a standard deviation of 13 . Tom has a score of 66 . Convert Tom's score to a \( z \)-score, rounded to the nearest hundredth.