Statistics Questions & Answers

Number of Words in a Novel The National Novel Writing Association states that the average novel is at least 50,000 words. A particularly ambitious writing club at a college-preparatory high school had randomly selected members with works of the following lengths. At \( \alpha=0.01 \), is there sufficient evidence to conclude that the mean length is greater than 50,000 words? Assume that the population is approximately normally distributed. \( 52,898 \quad 51,714 \quad 51,967 \quad 51,992 \quad 50,079 \quad 51,487 \quad 50,844 \) Send data to Excel

Question 5 If \( n-28, \bar{x}(x \)-bar \( )=39 \), and \( s=6 \), construct a confidence interval at a \( 80 \% \) confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.

5. Durante las semanas \( 1,2,3 \) y 4 del lanzamiento de un celular de moda, se venden: \( 1.8,3.2,4.2 \) y 4.8 millones de plezas respectivamente. a) ¿Sería útil para la empresa tener una fórmula que proporclone el número de celulares que se venden en cierta semana?

Question 4 You want to obtain a sample to estimate a population mean age of the incoming fall term transfer students. Based on previous evidence, you believe the population standard deviation is approximately \( \sigma=7 \). You would like to be \( 95 \% \) confident that your estimate is within 1.6 of the true population mean. How large of a sample size is required? Do not round between steps. Use technology to find z-score. Give your answer in whole people. Make sure you use the correct rounding rule for samples size. , Next Questions

You want to obtain a sample to estimate the proportion of a population that possess a particular genetic marker. Based on previous evidence, you believe approximately \( p^{*}=84 \% \) of the population have the genetic marker. You would like to be \( 98 \% \) confident that your estimate is within \( 4 \% \) of the true population proportion. How large of a sample size is required? Do not round mid-calculation. However, you may use a critical value accurate to three decimal places. Next Question

Suppose you flip two coins 100 times. The results are 40 both heads, 37 one head one tail, and 23 both fails. Are the coins fair? Test at a \( 5 \% \) significance level.

Assume that a sample is used to estimate a population proportion p. Find the \( 98 \% \) confidence interval for a sample of size 228 with \( 75.9 \% \) successes. Enter your answer as an open-interval (i.e., parentheses) using decimals (not percents) accurate to three decimal places. \( 98 \% \) C.I. - Answer should be obtained without any preliminary rounding. However, the critical value may be rounded to 3 decimal places.

Exercise 1: One hundred subjects in a psychological study had a mean score of \( M=35 \) on a test instrument designed to measure anger. The standard deviation of the \( n=100 \) test scores was \( \sigma=10 \). Find: a. A \( 99 \% \) confidence interval for the mean of the population the sample was selected.

A certain magazine published a study on how well firefighter gloves fit. In a group of 586 firefighters who reported their glove size, the researchers determined whether the gloves fit well or poorly, by gender. The data are summarized in the accompanying table. Consider the gender and glove fit status of a randomly selected firefighter. Complete parts a through f . A. male and glove fits well, male and glove fits poorly, female and glove fits well, female and glove fits poorly B. male and glove fits well, female and glove fits well C. male and glove fits well, male and glove fits poorly, female and glove fits well, female and glove fits poorly, no response D. male, female, glove fits well, glove fits poorly

A certain magazine published a study on how well firefighter gloves fit. In a group of 586 firefighters who reported their glove size, the researchers determined whether the gloves fit well or poorly, by gender. The data are summarized in the accompanying table. Consider the gender and glove fit status of a randomly selected firefighter. Complete parts a through \( f \). A. male and glove fits well, male and glove fits poorly, female and gitve fits well, female and glove fits poorly B. male and glove fits well, female and glove fits well C. male and glove fits well, male and glove fits poorly, female and glove fits well, female and glove fits poorly, no response D. male, female, glove fits well, glove fits poorly