A marketing researcher wants to estimate the mean amount spent per year​ ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of ​$58 and a standard deviation of ​$55. Complete parts​ (a) and​ (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from ​$51​? ​(Use a 0.01 level of​ significance.)   Identify the critical​ value(s).   ​(Type an integer or a decimal. Round to two decimal places as needed. Use a comma to separate answers as​ needed.)

An analyst found that the average amount of money in bank accounts at his/her bank is $2,000 with a standard deviation of $150.  What would be the variance?

A company wants to assess the average time it takes for customers to complete a particular task on their website. They collect the following data from a sample of 10 customers: 5, 6, 7, 8, 9, 10, 10, 11, 12, 13 minutes. Calculate the sample mean and standard deviation for this data.

According to the Center for Disease Control and Prevention (CDC), the mean life expectancy in 2015 for non‑Hispanic white males was 76.3 years. Assume that the standard deviation was 15 years, as suggested by the Bureau of Economic Research.The distribution of age at death, ????, is not normal because it is skewed to the left. Nevertheless, the distribution of the mean, x⎯⎯⎯, in all possible samples of size ???? is approximately normal if ???? is large enough, by the central limit theorem.Let x⎯⎯⎯ be the mean life expectancy in a sample of 100 non‑Hispanic white males. Determine the interval centered at the population mean ???? such that 95% of sample means x⎯⎯⎯ will fall in the interval. Give your answers precise to one decimal.

Suppose there is a city where the mean cost per month of a one-bedroom apartment is $1,500, with a standard deviation of $250. Approximately what percentage of one-bedroom apartments in the city cost between $750 and $1,000?

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?

Suppose there is a city where the mean cost per month of a one-bedroom apartment is $1,500, with a standard deviation of $250.  Approximately what percentage of one-bedroom apartments in the city cost between $750 and $1,000?

The average McDonald's restaurant generates $2.6 million in sales each year with a standard deviation of 1. Tatiana wants to know if the average sales generated by McDonald's restaurants in Alaska is different than the worldwide average. She surveys 25 restaurants in Alaska and finds the following data (in millions of dollars):3.2, 1.8, 0.9, 3.2, 3.6, 1.7, 4.2, 2, 3.1, 3.9, 3, 2.9, 2.5, 3.5, 3, 3, 2.4, 5, 3.8, 0.9, 2.2, 2.4, 2.6, 2.8, 3.3Perform a hypothesis test using a 10% level of significance.  Find the pp-value of the point estimate. P(p(    <or >    )=  P(z<)=P(    ?    )=)=? p value =?pp-value==

Is it worth pursuing a doctoral degree in education if you already have an undergraduate degree? One way to help make this decision is to look at the mean incomes of these two groups. Suppose that 11 people with bachelor’s degrees in education were surveyed. Their mean annual salary was $45,000 with a standard deviation of $9700. Seventeen people with doctoral degrees in education were found to have a mean annual salary of $31,000 with a standard deviation of $10,000. Assume that the population variances are not the same. Construct a 95% confidence interval to estimate the true difference between the mean salaries for people with doctoral degrees and undergraduate degrees in education. Let Population 1 be the salaries for people with doctoral degrees and Population 2 be the salaries for people with undergraduate degrees. Round the endpoints of the interval to the nearest whole number, if necessary. LOWER AND UPPER ENDPOINT

4. A college instructor gave identical tests to two randomly sampled groups of 50 students. One group took the test on paper and the other took it online. Those who took the test on paper had an average score of 75.0 with a standard deviation of 12.5. those who took the test online had an average score of 78.0 with a standard deviation of 14.0. can you conclude that the mean scores differ between online and paper tests?