Your research group has been hired to study student satisfaction with the dining halls at Illinois State University and your group has determined that 95% of female students are satisfied with their dining services while 55% of male students are satisfied with their the dining services. The sample size of females is 150 students and the sample size of males is 250 students for this study. Based on this information, your research group calculates the z-score to be: [___).

The authors of a paper compared two different methods for measuring body fat percentage. One method uses ultrasound, and the other method uses X-ray technology. Body fat percentages using each of these methods for 16 athletes (a subset of the data given in a graph that appeared in the paper) are given in the accompanying table. You can assume that the 16 athletes who participated in this study are representative of the population of athletes. Athlete X-ray Ultrasound 1 5.00 4.25 2 12.00 8.75 3 9.25 9.00 4 12.00 11.75 5 17.25 17.00 6 29.50 27.50 7 5.50 6.50 8 6.00 6.75 9 8.00 8.75 10 9.50 10.50 11 9.25 9.50 12 11.00 12.00 13 12.00 12.25 14 14.00 15.50 15 17.00 18.00 16 18.00 18.25   Use these data to estimate the difference in mean body fat percentage measurement for the two methods. Use a confidence level of 95%. (Use ?d = ?X-ray − ?ultrasound. Round your answers to three decimal places.)     ,     % Interpret the interval in…

As an admissions counselor, I am interested in understanding whether or not there is a difference in stress levels not only between different majors but also between different classes (Freshman v. Seniors). I gather the following data from students from three majors (Psychology, Chemistry, and Engineering), that are in their freshmen or senior years and ask them about their stress levels (scale of 1-10, with lower numbers meaning less stress). Using the data below, test whether there are effects of class, major, or an interaction between them at an alpha of 0.05.    Psychology Chemistry Engineering Freshmen 3, 4, 4, 2, 4 4, 5, 7, 8, 4 5, 7, 7, 8, 5 Senior 4, 5, 5, 3, 5 8, 5, 6, 7, 7 9, 9, 8, 7, 9 Complete the ANOVA summary table below:  Source SS df MS (variance) F MAJOR         CLASS         MAJOR*CLASS         ERROR/RESIDUAL       Nothing here TOTAL     Nothing here Nothing here   What can we conclude?…

The director of student services at Oxnard College is interested in whether women are less likely to attend orientation than men before they begin their coursework. A random sample of freshmen at Oxnard College were asked what their gender is and whether they attended orientation. The results of the survey are shown below: Data for Gender vs. Orientation Attendance Women Men 431 187 Yes 442 No 214 What can be concluded at the ax = 0.10 level of significance? For this study, we should use Select an answer a. The null and alternative hypotheses would be: Ho: Select an answer Select an answer Select an answer (please enter a decimal and note that p1 and μl represent the proportion and mean for women and p2 and 2 represent the proportion and mean for men.) H₁: Select an answer Select an answer Select an answer (Please enter a decimal) (please show your answer to 3 decimal places.) b. The test statistic c. The p-value = d. The p-value is ? a e. Based on this, we should Select an answer the…

Studies indicate that excessive noise at night can affect weight gain. One study of n = 127 rats compared the weight gain of rats exposed to excessive noise at night and the weight gain of rats in a quiet night environment. Sample statistics for the study are given in the table below. Use this information to determine if there is significant evidence that weight gain of rats exposed to excessive noise at night is different on average than weight gain of rats in a quiet night environment.        Excessive noise at night environment  (Group 1)   Quiet night environment  (Group 2) Sample mean (grams) 22.4 19.9 Sample standard deviation (grams) 6.4 3.8 Observations/Sample size 69 58       The 95% confidence interval for the difference (Group 1 – Group 2) in weight gain of rats exposed to excessive noise at night and rats in quiet night environment is (0.7g, 4.3g). Interpret this confidence interval in one or two sentences.

2. Metal Tags on Penguins and Survival. Data were collected over a 10-year timespan from a sample of 100 penguins that were randomly given either metal or electronic tags. One variable examined is the survival rate 10 years after tagging. The scientists observed that 10 of the 50 metal tagged penguins survived, compared to 18 of the 50 electronic tagged penguins. Test whether the survival rate is lower among metal- tagged penguins than among electronic-tagged penguins. Use subscripts E for Electronic and M for Metal. a. State hypotheses. b. Calculate the sample statistic PE - PM c. Use Normal distribution methods to calculate a z-test statistic, given SE = 0.0898. d. Find the p-value and draw a Normal curve with z-statistic and appropriate shaded region. Normal curve: p-value: e. State the conclusion of the test in context, using nontechnical language. f. Find a 90% confidence interval to three decimal places for this difference in proportions, given SE= 0.08836. Show your…

Mr. Acosta, a sociologist, is doing a study to see if there is a relationship between the age of a young adult (18 to 35 years old) and the type of movie preferred. A random sample of 93 adults revealed the following data. Test whether age and type of movie preferred are independent at the 0.05 level. Movie Drama Science Fiction Comedy Column Total 18-23 yr 10 12 8 30 Person's Age 24-29 yr 11 10 10 31 30-35 уг 13 8. 11 32 Row Total 34 30 29 93 (a) What is the level of significance? State the null and alternate hypotheses. Ho: Age and movie preference are not independent. H7: Age and movie preference are independent. H,: Age and movie preference are not independent. H: Age and movie preference are not independent. • Ho: Age and movie preference are independent. H: Age and movie preference are not independent. O Ho: Age and movie preference are independent. H,: Age and movie preference are independent. (b) Find the value of the chi-square statistic for the sample. (Round the expected…

Studies indicate that excessive noise at night can affect weight gain. One study of n = 127 rats compared the weight gain of rats exposed to excessive noise at night and the weight gain of rats in a quiet night environment. Sample statistics for the study are given in the table below. Use this information to determine if there is significant evidence that weight gain of rats exposed to excessive noise at night is different on average than weight gain of rats in a quiet night environment.        Excessive noise at night environment  (Group 1)   Quiet night environment  (Group 2) Sample mean (grams) 22.4 19.9 Sample standard deviation (grams) 6.4 3.8 Observations/Sample size 69 58       The p-value for this test is 0.0086. Make a decision and conclusion for the hypothesis test in context. Use a 5% significance level (α = 0.05).

In a One-way Between Subject ANOVA, the number of levels the IV had was 3, and the within/error degrees of freedom was 48. What was the total number of people in the participants analyzed in the study

The leader of two postpartum women’s support groups is interested in the depression levels of the women in her groups. She administers the Center for Epidemiologic Studies Depression Scale (CES-D) screening test to the members of her groups. The CES-D is a 20-question self-test that measures depressive feelings and behaviors during the previous week. The mean depression level from the screening test for the 10 women in the first group is μ₁ = 16; the mean depression level for the 14 women in the second group is μ₂ = 10. Without calculating the weighted mean for the combined group, you know that the weighted mean is: