In a random sample taken from 3 high schools in Albany area the mean GPA of female seniors (N = 526) is 2.92 with the standard deviation of 1. The mean GPA of male seniors (N = 477) is 2.77 with the standard deviation of 1.2. If you want to test whether female high school seniors in Albany (Sample 1) have lower GPA than male high school seniors (Sample 2), your alternative hypothesis would be: %3D %3D O H1: µ1 < µ2 O H1: µ1 # 2.77 O H1: µ1 > µ2 H1: µ1 # p2

You may need to use the appropriate technology to answer this question. Is there any difference in the variability in golf scores for players on a women's professional golf tour and players on a men's professional golf tour? A sample of 20 tournament scores from events in a tour for women showed a standard deviation of 2.4671 strokes, and a sample of 30 tournament scores from events in a tour for men showed a standard deviation of 2.2182. Conduct a hypothesis test for equal population variances to determine if there is any statistically significant difference in the variability of golf scores for male and female professional golfers. Use a = 0.10. State the null and alternative hypotheses. Ho: Find the value of the test statistic. (Round your answer to two decimal places.) Find the p-value. (Round your answer to four decimal places.) p-value = State your conclusion. O Reject Ho. We cannot conclude that there is a difference in the variability of golf scores for male and female…

A forestry researcher is conducting a study of trees in the upper midwest. He selects a random sample of 125 red maple trees and measures the trunk diameter of each. The mean of the sample is 25 inches with a standard deviation of 5.2 inches, use this to find a 95% confidence interval for the mean trunk diameter of all red maple trees.

It currently takes users a mean of 12 minutes to install the most popular computer program made by RodeTech, a software design company. After changes have been made to the program, the company executives want to know if the new mean is now different from 12 minutes so that they can change their advertising accordingly. A simple random sample of 91 new customers are asked to time how long it takes for them to install the software. The sample mean is 11.7 minutes with a standard deviation of 1.6 minutes. Perform a hypothesis test at the 0.05 level of significance to see if the mean installation time has changed.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to three decimal places.

A sample of 76 female workers and another sample of 48 male workers from a state produced mean weekly earnings of $743.50 for the females and $777.63 for the males. Suppose that the population standard deviations of the weekly earnings are $80.05 for the females and $88.68 for the males. The null hypothesis is that the mean weekly earnings are the same for females and males, while the alternative hypothesis is that the mean weekly earnings for females is less than the mean weekly earnings for males. Directions: • Label your answers with the correct statistical symbols. • If you use the Ti, identify which function and values you used to calculate. If you solve by hand, show all steps 2.5 The significance level for the test is 1%. What is/are the critical value(s)? 2.6. What is the value of the test statistic, rounded to three decimal places? 2.7. What is the p-value for this test, rounded to four decimal places? 2. 8. Using the p-value approach, do you reject or fail to reject the null…

You are interested in studying the average gestational length of pregnancies among African American women in the United States to see if it is different from the rest of the US population. The population mean for gestational length is 39 weeks with a standard deviation of 2 weeks. You take a simple random sample of 22 African American women that gave birth in the last year and find that their mean gestational length is is 38.5 weeks. If you decide to conduct a two-sided test with α = .05. What is the power of this test?

You would like to estimate the variance of sick days at a Fortune 500 company.  You randomly select 15 employees and record how many sick days they have used in the past year and you get a sample standard deviation of 1.2.  Provide a 95% confidence interval estimate of the population variance.

It currently takes users a mean of 5 minutes to install the most popular computer program made by RodeTech, a software design company. After changes have been made to the program, the company executives want to know if the new mean is now different from 5 minutes so that they can change their advertising accordingly. A simple random sample of 46 new customers are asked to time how long it takes for them to install the software. The sample mean is 4.7 minutes with a standard deviation of 1.1 minutes. Perform a hypothesis test at the 0.10 level of significance to see if the mean installation time has changed. Step 3 of 3: Draw a conclusion and interpret the decision. E Tables E Keypad Answer Keyboard Shortcuts We reject the null hypothesis and conclude that there is insufficient evidence at a 0.10 level of significance that the new mean installation time is different from 5 minutes and that RodeTech may need to change their advertising. We fail to reject the null hypothesis and conclude…

The College Board reports that the scores on the math SAT were normally distributed with a mean of 525. A random sample of 15 students at your high school had a mean of 550 and a sample standard deviation of 105.   What values of the sample mean would lead to rejection of the null hypothesis at the 0.01 level of significance?

In a school district, all sixth grade students take the same standardized test. The superintendant of the school district takes a random sample of 3030 scores from all of the students who took the test. She sees that the mean score is 169169 with a standard deviation of 7.06747.0674. The superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 1313. Is there evidence that the standard deviation of test scores has decreased at the α=0.005α=0.005 level? Assume the population is normally distributed. Step 1 of 5:  State the null and alternative hypotheses. Round to four decimal places when necessary. Step 2 of 5:  Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places.     Step 3 of 5:  Determine the value of the test statistic. Round your answer to three decimal places. Step 4 of 5:  Make the…