In a study of computer use, 1000 randomly selected Canadian Internet users were asked how much time they spend using the Internet in a typical week. The mean of the sample observations was 12.6 hours. (a) The sample standard deviation was not reported, but suppose that mean time spent using the Internet by Canadians is greater than 12.4 hours. (Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to three decimal places.) was 4 hours. Carry out a hypothesis test with a significance level of 0.05 to decide if there is convincing evidence that the t = P-value =

An instructor claims that the average number of hours needed to study for a final exam in order to pass should be 5 hours. A student believes that the instructor is understating the number of hours needed to pass and surveys 36 students and finds the sample mean and standard deviation to be 5.7  and 1.5 hours respectively.  Test the instructors claim at a .10 level.

Jeff is doing an experiment involving mice. The mice weights have mean weight 2.37 ounces and standard deviation 0.053 ounces. Jeff selects 9 mice independently and calculates the sample mean, x̄, of their weights. What is the standard deviation of x̄?

According to one study, the average hours of sleep on a weeknight for men was 6.9 hours with a standard deviation of 1.5 hours. These hours are normally distributed.  c. Find the proportion of men who sleep between 6-8 hours per night.  d. Find the number of hours that represents the 90th percentile.

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?

In the class of 2019, more than 1.6 million students took the SAT. The distribution of scores on the math section (out of 800) is approximately normal with a mean of 528 and standard deviation of 117.  What proportion of students earned scores between 500 and 600 on the SAT math test?

The director of research and development is testing a new medicine. She wants to know if there is evidence at the 0.02 level that the medicine relieves pain in more than 346 seconds. For a sample of 58 patients, the mean time in which the medicine relieved pain was 352 seconds. Assume the population standard deviation is 23. Find the P-value of the test statistic. 囲 Tables E Keypad Keyboard Shortcuts 0.0582 %3D IX

Last year, the average amount that teams for the Statistics Games raised was $375. Have teams been more successful at fundraising this year? To find out, you take a random sample of 36 teams. Your sample of 36 teams yields a mean of $396 and a standard deviation of $70. Might you have made a Type 1 or Type 2 error? A Type 1. This means that we said that the mean amount raised had increased, when it was actually still $375. B You might have made a calculation error. C Neither- we're sure the average has increased. D Type 2. This would mean that we said there was not enough evidence to say the mean had increased from $375, when it actually is higher than $375. E Either kind is possible!

Which is cheaper: eating out or dining in? The mean cost of a flank steak, broccoli, and rice bought at the grocery store is $13.04 (Money.msn website, November 7, 2012). A sample of 100 neighborhood restaurants showed a mean price of $12.75 and a standard deviation of $2 for a comparable restaurant meal. Answer questions 4-7.

The ages of the employees at Solar Systems, Inc. is normally distributed with a mean of 32.7 years and a standard deviation of 1.8 years. What percentage of employees at Solar Systems, Inc. are younger than 30 years old? Round your answer to the nearest tenth of a percent.