Elite (n = 16) University (n = 13) Quality x S x S Sprint 27.3 0.7 26.0 1.5 speed (km/hr) Peak heart 192.0 6.0 193.0 6.0 rate (bpm) Intermittent 1160 191 781 129 recovery test (m) Carry out the significance tests using α = 0.05. Report the test statistics and P-values and write a short summary of your conclusion. (Software gives k = 16.2, 25.8, and 26.2, respectively.)

Fuel Economy A company with a large fleet of cars hopes to keep gasoline cost down and sets a goal of attaining a fleet average of greater than 26 miles per gallon. To see if their goal is being met, they check the gasoline usage of 50 company trips, finding a mean of 27.01 miles per gallon. Define the relevant parameter, state the null and alternative hypothesis, and test at the 5% significance level to see whether this sample provides evidence that the company is meeting its goal. The standard error from the randomization distribution under the null hypothesis is SE = 0.68.

A forensic psychologist is interested in testing whether serial killers are more introverted than the general population. A sample of 16 serial killers serving life sentences was tested and found to have a sample mean introversion score of 41 and a standard deviation (s) of 10. The population mean (µ) for introversion is 36. Show calculations for the appropriate test  What are the null and alternative hypotheses?   What significance test did you use? Using an alpha level of .05, determine whether the sample was significantly different from population.   Report and interpret an effect size.   Given your conclusion in part b, what type of error might you be making?

An analyst believe that the average return of all Ghana stock was less than 4. The sample size of 36 observation with a sample mean of 3 and the population standard deviation is 2. Will the analyst reject the null hypothesis at 5% level of significance? (p-value approach)

We want to test the hypothesis that there is a significant difference between the mean BMI of regular soda drinkers in 2015 and 2018. The mean BMI for regular soda drinkers in 2015 was 26.5. In 2018, the researcher gathered a sample of 62 regular soda drinkers, measuring their BMIs and found the average BMI was 29 with a SD of 5.5. Conduct a hypothesis test at 0.05 alpha level. Determine our test statistic, pvalue and conclusion.

A sample of 50 cans of tomatoes are tested for levels of the chemical BPA to see if there is evidence that the mean level is greater than 100 ppb (parts per billion). a. Write down the hypotheses for this test (Do not forget to define the parameters): b. Give a possible sample mean that you think would show strong evidence against the null hypothesis and in support of the alternative hypothesis:

A new drug, Drug X, is being tested in a clinical trial to treat patients with high blood pressure. To determine the effectiveness of Drug X, 100 patients are randomly selected and their blood pressure, in millimeters of Hg, are recorded. They are then prescribed with the drug for 10 weeks. After 10 weeks, their blood pressure is recorded again. Which of the following would be the BEST test to use on this type of scenario, assuming the assumptions are met?    Two independent sample proportion z-test Chi-square test of homogeneity Analysis of Variance (ANOVA) Paired t-test Chi-square test of independence Two independent sample mean t-test

Before a company decides to purchase a large quantity of a solvent, it would like to see substantive evidence that the mean value of an impurity-forming substance is less than 1.0 ppb. What is the hypothesis to be tested here? What are the type I and type II statistical errors that can be made in this regard?

The Testing Center creates standardized exams for a variety of quantitative disciplines, including business statistics. Recently the Testing Center received complaints from faculty who have used its latest business statistics test saying the mean time required to complete the exam exceeds the advertised mean of 40 minutes.  Before responding, employees at the Testing Center plan to test this claim using an alpha level equal to 0.05 and a random sample size of n = 100 business statistics students. Based on previous studies, suppose that the population standard deviation is known to be σ = 8 minutes. Suppose that the sample of 100 students produced a sample mean of 43.5 minutes. Conduct the hypothesis test to determine whether the mean time required to complete the exam exceeds the advertised mean of 40 minutes. Formulate the null and alternative hypotheses. The decision rule in terms of the critical value of the test statistic.  The calculated value of the test statistic.