16. A 5 -member executive committee is to be formed from a 7 -member board of directors. In how many ways can it be formed? a. 26 b. 21 c. 120 d. 2520

A doctor wants to estimate the mean HDL cholesterol of all 20 - to 29 -year-old females. How many subjects are needed to estimate the mean HDL cholesterol within 4 points with \( 99 \% \) confidence assuming \( \mathrm{s}=17.5 \) based on earlier studies? Suppose the doctor would be content with \( 90 \% \) confidence. How does the decrease in confidence affect the sample size required? A \( 99 \% \) confidence level requires the icon to view a partial table of critical values.

4.- Un fabricante de reproductores de discos compactos utiliza un conjunto de pruebas amplias para evaluar la funcion eléctrica de su producto. Todos los reproductores de discos compactos deben pasar tadas las pruebas antes de venderse. Una muestra aleatoria de 500 repraductores tiene como resultado 15 que falan en una o mas pruebas Encuentre un intervalo de confianza de \( 90 \% \) para la proporión de los reproductores de discos compactos de la poblacion que no pasen todas las pruebas.

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 20 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 \( \bar{x}=8.14 \mathrm{~cm}^{3} \) and \( \mathrm{s}=0.7 \mathrm{~cm}^{3} \). Conduct the appropriate test at the \( \alpha=0.01 \) level of significance. Identify the P-value. P-value \( =0.000 \) (Round to three decimal places as needed.) Make a conclusion regarding the hypothesis. \( \square \mathrm{cm}^{3} \).

Researchers selected 872 patients at random among those who take a certain widely-used prescription drug daily. In a clinical trial, 27 out of the 872 patients complained of flulike symptoms. Suppose that it is known that \( 2.7 \% \) of patients taking competing drugs complain of flulike symptoms. Is there sufficient evidence to conclude that more than \( 2.7 \% \) of this drug's users experience flulike symptoms as a side effect at the \( \alpha=0.1 \) level of significance? Because \( n p_{0}\left(1-p_{0}\right)=\square \) selected at random, all of the requirements for testing the hypothesis \( \square \) satisfied. (Round to one decimal place as needed.)

A survey was conducted that asked 1022 people how many books they had read in the past year. Results indicated that \( \bar{x}=15.8 \) books and \( s=18.3 \) books. Construct a \( 90 \% \) confidence interval for the mean number of books people read. Interpret the interval. Construct a \( 90 \% \) confidence interval for the mean number of books people read and interpret the result. Select the correct choice below and fill in the answer boxes to complete your choice. (Use ascending order. Round to two decimal places as needed.) A. There is \( 90 \% \) confidence that the population mean number of books read is between B. If repeated samples are taken, \( 90 \% \) of them will have a sample mean between C. There is a \( 90 \% \) probability that the true mean number of books read is between \( \square \) and