Some college graduates employed full-time work more than 40 hours per week, and some work fewer than 40 hours per week. We suspect that the mean number of hours worked per week by college graduates, u, is different from 40 hours and wish to do a statistical test. We select a random sample of college graduates employed full-time and find that the mean of the sample is 44 hours and that the standard deviation is 4 hours. Based on this information, answer the questions below. What are the null hypothesis (H.) and the alternative hypothesis (H,) that should be used for the test? H,: u is ? |H: µ is ? ? In the context of this test, what is a Type I error? v when, in A Type I error is ? fact, u is ? v the hypothesis that u is ? ? v. Suppose that we decide to reject the null hypothesis. What sort of error might we be making? ?

The results of a common standardized test used in psychology research is designed so that the population mean is 175 and the standard deviation is 20. A subject earns a score of 227. What is the z-score for this raw score? Do not round your answer.z-score =    ?

According to the U.S. Census, the average adult woman is the United States is 65 inches tall and the standard deviation is 3 inches.  If Zsike is 67 inches tall, what is her z-score?

You may need to use the appropriate technology to answer this question. Data were collected on the top 1,000 financial advisers. Company A had 239 people on the list and another company, Company B, had 121 people on the list. A sample of 16 of the advisers from Company A and 10 of the advisers from Company B showed that the advisers managed many very large accounts with a large variance in the total amount of funds managed. The standard deviation of the amount managed by advisers from Company A was s₁ = $583 million. The standard deviation of the amount managed by advisers from Company B was s₂ = $484 million. Conduct a hypothesis test at a = 0.10 to determine if there is a significant difference in the population variances for the amounts managed by the two companies. What is your conclusion about the variability in the amount of funds managed by advisers from the two firms? State the null and alternative hypotheses. 2 2 H₂:0 2 Find the value of the test statistic. (Round your answer…

Please help me understand the problem. Is the given standard deviations 6, and 7? I know I need to use the unit normal table, and shade the curve. But how? Thanks.

Please see the picture below. None of the answers I've tried is coming back right. I just need help with the items in the red boxes.

I need help understanding how to solve the question with a black box around it.

I'm started doing these, but I'm not sure if they are set up right. I am confused about the difference between a true variance and a sample standard deviation.

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

A sample of 281 Al products sold at The Yes Buy located at Finch and Keele has a mean of $74.83 and a median of $68.88. Later, it was discovered that an observation which was recorded incorrectly as "$90.25" but the actual value should be "$95.75". If we make this correction to the data, then what is the sample mean, median, mode and standard deviation?