To evaluate the effect of a treatment, a sample is ob- tained from a population with a mean of u= 40, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M =44.5 with a variance of s2 = 36. If the sample consists of n = 4 individuals, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05? b. If the sample consists of n = 16 individuals, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05? c. Comparing your answers for parts a and b, how does the size of the sample influence the outcome of a hypothesis test?

A teacher is interested in assessing whether or not there is the same amount of variance in the scores of a particular type of test between male and female students. She believes that the variance for girls is higher than it is for boys. After grading the test she measures the following:  In her class, 15 boys had a variance of 460 and 13 girls had a variance of 1,400. Set up hypotheses to test if the teacher’s assumption that the girls’ variance of scores on the test is higher than the boys’ variance. Perform the appropriate test and fully state your results.

Do men take a different amount of time than women to get out of bed in the morning? The 45 men observed averaged 6.1 minutes to get out of bed after the alarm rang. Their standard deviation was 5.6. The 42 women observed averaged 6 minutes, and their standard deviation was 4 minutes. What can be concluded at the a = 0.01 level of significance? Assuming Equal Variances a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: Select an answer Select an answer Select an answer v (please enter a decimal) H1: Select an answer v Select an answer Select an answer v (Please enter a decimal) c. The test statistic ? d. The test statistics (please show your answer to 3 decimal places.) N

Airline companies are interested in the consistency of the number of babies on each flight so that they have adequate safety equipment. They are also interested in the variation in the number of babies. Suppose that an airline executive believes the average number of babies on flights is six with a variance of nine at most. The airline conducts a survey. The results of the 18 flights surveyed give a sample average of 6.4 with a sample standard deviation of 3.9. To test the null hypothesis against the alternative hypothesis one relies on the chi-squared test. What is the Test Statistic?     a. 18.37   b. 47.38   c. 9.26   d. 28.73

Say we were testing the effects of taking calcium on bone density levels and obtained a positive and significant value for our independent t test result. What would you write (using APA format) when performing a percentage of variance explained test on the data and received a value of r2=.38.

Using traditional methods it takes 8.2 hours to receive a basic flying license. A new license training method using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique on 26 students and observed that they had a mean of 8.0 hours with a variance of 2.89. Is there evidence at the 0.1 level that the technique reduces the training time? Assume the population distribution is approximately normal. Step 5 of 5: Make the decision to reject or fail to reject the null hypothesis.

Over the years, a sushi restaurant has had a mean customer satisfaction rating of 72.5 with a variance of 24.7. The owner has hired you to perform a hypothesis test to see if using a new menu will have any effect on the variance, o“. To do so, you survey a random sample of 19 customers who ordered from the new menu. For the customers surveyed, the variance of ratings is 44.3. Under the assumption that the customer ratings using the new menu follow a normal distribution, you will perform a chi-square test. Find x, the value of the test statistic for your chi-square test. Round your answer to three or more decimal places.

At age 9 the average weight for both boys and girls are exactly the same. A random sample of 9 year olds gave the following results....                                   Boys:                Girls:Sample Size:               65                     50Mean weight (lbs):      130                   125Pop. Variance:            120                   130 At alpha 0.05, do the data support the claim that there is a difference in heights?

An electronic company's records show that the mean number of circuit.boards rejected per batch is 5.7 with a variance of 1.4. Due to a change in the molding process, factory management has hired you to perform a hypothesis test to check if the variance, o, has increased. To do so, you test a random sample of 10 batches produced using the new process; the number of circuit boards rejected per batch has a sample variance of 2.5. Under the assumption that the number of circuit boards rejected per batch using the new process follows a normal distribution, you will perform a chi-square test. Find x, the value of the test statistic for your chi-square test. Round your answer to three or more decimal places. * = 0

The accompanying table lists pulse rates. Use a 0.05 significance level and apply the methods of two-way analysis of variance. What is the conclusion? Click on the icon to view the data table. State the null and alternative hypotheses in the test for the effect of an interaction between row and column factors. Ho: There interaction between gender and age. H₁: There interaction between gender and age. Pulse Rates for Gender and Age C Under 30 Years of Age Over 30 Years of Age Female 78 103 78 63 61 98 81 98 91 95 77 75 73 65 71 78 61 71 74 55 Female Male 60 81 56 69 68 74 75 68 63 56 46 70 61 65 91 80 59 58 64 59 Male Print Done D