A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean cre score is 706.1 . A credit analyst wondered whether high-income individuals (incomes in excess of \( \$ 100,000 \) per year) had higher credi scores. He obtained a random sample of 45 high-income individuals and found the sample mean credit score to be 719.6 with a standard deviation of 84.2 . Conduct the appropriate test to determine if high-income individuals have higher credit scores at the \( \alpha=0.05 \) level of significance. Click the icon to view the table of critical t-values. Identify the t-statistic. \( t_{0}=\square \) (Round to two decimal places as needed.)

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

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

Scores on a test have a mean of 89 and a standard deviation of 7 . Calvin has a score of 79. Convert Calvin's score to a \( z \)-score, rounded to the nearest hundredth.

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

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