Harper's Index reported that 80% of all supermarket prices end in the digit 9 or 5. Suppose you check a random sample of 112 items in a supermarket and find that 87 have prices that end in 9 or 5. Does this indicate that fewer than 80% of the prices in the store end in the digits 9 or 5? Use α = 0.05. 1. What is the value of the sample test statistic? (Round your answer to two decimal places.) 2. Find the P-value of the test statistic. (Round your answer to four decimal places.)

In order to set rates, an insurance company is trying to estimate the number of sick days that full time workers at an auto repair shop take per year. A previous study indicated that the standard deviation was  2.4  days. How large a sample must be selected if the company wants to be  95%  confident that the true mean differs from the sample mean by no more than  1  day?     40     29     17     23

You are conducting a study to see if the mean doctor's salary (in thousands of dollars) is significantly more than 89. A random sample of 27 doctors' salary in thousands of dollars is shown below. Test the claim using a 1% level of significance. Give answer to at least 4 decimal places.   Salary 102.57 87.59 99.36 96.89 93.53 85.75 100.46 85.57 90.56 85.12 83.49 99.11 99.53 85.62 89.55 96.33 90.95 84.41 91.69 96.33 85.25 87.77 78.22 91.21 96.93 85.36 85.35   What are the correct hypotheses? H0: Select an answer σ p̂ μ s² s x̄ p σ²  ? ≥ > ≤ ≠ = <   thousand dollarsH1: Select an answer x̄ p̂ μ p σ σ² s² s  ? = > ≠ ≥ ≤ <   thousand dollars Based on the hypotheses, find the following:Test Statistic = Critical-value =  Shade the sampling distribution curve with the correct critical value(s) and shade the critical regions. The arrows can only be dragged to t-scores that are accurate to 1 place after the decimal point…

In order to set rates, an insurance company is trying to estimate the number of sick days that full time workers at an auto repair shop take per year. A previous study indicated that the standard deviation was  3.3  days. How large a sample must be selected if the company wants to be  99%  confident that the true mean differs from the sample mean by no more than  1  day?     73     157     90     52

To build a 95% CI for the mean of a population, you take a random sample and find these values: 18.4 19.8 17 18.6 23 21.7 18.9 14.3 17.6 21.2 21.4 23.4 20 20.7 15.2 21.9 21 What is the CI? Enter like this: (min,max) Be sure to use the parentheses or you will be marked wrong. Keep at least 3 decimals in all intermediate steps, and round your answer to two decimals. Submit Question

Consider a set of data in which the sample mean is 27 and the sample standard deviation is 6.2. Calculate the z-score given that x = 28.5. Round your answer to two decimal places. An

2. The population standard deviation for the age of Fictional College students is 8.4 years. If we want to be 95% confident that the sample mean age is within one year of the true population mean age of Fictional College students, how many randomly selected Fictional College students must be surveyed?

Is the difference between the mean annual salaries of registered nurses in State A and State B equal to $10,500? To decide, you select a random sample of registered nurses from each state. The results of each survey are shown. Assume the population standard deviations are o, = $8337 and o, = $7633. At a = 0.01, what can you conclude? Registered Nurses in State A Registered Nurses in State B 75,695 70,695 %3D %3D X1 X2 n1 30 n2 25 What are the null and alternative hypotheses for this test? A. Ho: H1 - H22 10,500 Ha: H1 - H2 10,500 Ha: H1 - H2s 10,500 O F. Ho: H1 - H2 S 10,500 Hai H1 - H2 > 10,500 Determine the critical value(s). (Round to three decimal places as needed. Use a comma to separate answers as needed.)

According to an expert for the automotive industry, 68% of Americans know how to drive a manual transmission vehicle. Suppose 220 Americans are sampled. (Give results accurate to at least 4 decimal places.) a. Of the 220 people sampled, 160 respond that they know how to drive a manual transmission vehicle. What is the sample statistic p? p = b. Under the assumption that the industry expert's claim that 68% of Americans know how to drive a manual transmission vehicle is valid, what is the probability that the survey in part (a) would result in a p that is at least as high as the one found? c. Under the assumption that the industry expert's claim that 68% of Americans know how to drive a manual transmission vehicle is valid, what is the probability that the survey in part (a) would result in a p that is between 66% and 71%?