In Exercises 5–20, assume that the two samples are independent simple random samples selected from
13. Are Male Professors and Female Professors Rated Differently?
a. Use a 0.05 significance level to test the claim that two samples of course evaluation scores are from populations with the same
b. Using the summary statistics given in part (a), construct a 95% confidence
c. Example 1 used similar sample data with
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Essentials of Statistics (6th Edition)
- Answer A, B1, and B2: A. The National Institute of Mental Health published an article stating that in any one-year period, approximately 9.5 percent of American adults suffer from depression or a depressive illness. Suppose that in a survey of 100 people in a certain town, seven of them suffered from depression or a depressive illness. Conduct a hypothesis test to determine if the true proportion of people in that town suffering from depression or a depressive illness is lower than the percent in the general adult American population. B. Researchers interested in lead exposure due to car exhaust sampled the blood of 52 police officers subjected to constant inhalation of automobile exhaust fumes while working traffic enforcement in a primarily urban environment. The blood samples of these officers had an average lead concentration of 124.32 µg/l and a SD of 37.74 µg/l; a previous study of individuals from a nearby suburb, with no history of exposure, found an average blood level…arrow_forwardDetermine the hypothesis using apa formatarrow_forwardA student is eludying the migration pattems of several birds. She collects the data in the table. of rd () 3.0 Distasce Traveled (on) 276 4.5 10.0 1,909 2,356 25.0 What conclusion can the student make? (SC.5.N.1.1) O The distances bird travel is independent of their size. O Birds more than ten grams in weight are more likely to travel. O The smallest bird traveled the greatest distance. O The largest birds stay in the same habitat all year.arrow_forward
- Health care workers who use latex gloves with glove powder on a daily basis are particularly susceptible to developing a latex allergy. Each in a sample of 47 hospital employees who were diagnosed with a latex allergy based on a skin-prick test reported on their exposure to latex gloves. Summary statistics for the number of latex gloves used per week are x = 19.3 and s = 12.3. Complete parts (a) - (d). a. Give a point estimate for the average number of latex gloves used per week by all health care workers with a latex allergy. b. Form a 95% confidence interval for the average number of latex gloves used per week by all health care workers with a latex allergy. (Use integers or decimals for any numbers in the expression. Round to two decimal places as needed.) с. Gi a practical interpretation of the interval, part (b). A. One can be 95% confident that latex gloves cause allergies for all who use a number of gloves contained in the interval. B. One can be 95% confident that the average…arrow_forwardA large manufacturing company producing air conditioner compressor believes the number of units of air conditioner sold is related to atmospheric temperature. An R&D officer conducted a study and gathered the following data: 3. Day Sale Temperature (Fahrenheit) 63 (in thousands) 1.52 1 2 70 1.68 3 73 1.8 4 75 2.05 80 2.36 6. 82 2.25 7 85 2.68 8 88 2.9 9. 90 3.14 3.06 3.24 10 91 11 92 12 75 1.92 13 98 3.4 14 100 3.28 Construct an estimated regression line between temperature and number of units sold. а) b) Does the model in part (a) confirm that contribution of temperature to number of units of air conditioner sold? Test using a 0.05. Find the coefficient of correlation. What does the value imply about the relationship of the two variables? c) If the temperature soared to 120 Fahrenheit, can you predict the number of units of air conditioner sold? Explain d)arrow_forwardWinter visitors are extremely important to the economy of Southwest Florida. Hotel occupancy is an often-reported measure of visitor volume and visitor activity. Hotel occupancy data for February in two consecutive years are as follows. current year previous year occupied rooms 1470 1458 total rooms 1750 1800 a.) Formulate the hypothesis test that can be used to determine if there has been an increase in the proportion of rooms occupied over the one-year period. b.) What is the estimated proportion of hotel rooms occupied each year? c.) Using a 0.05 level of significance, what is your hypothesis test conclusion? What is the p-value? d.) What is the 95% confidence interval estimate of the change in occupancy for the one-year period?arrow_forward
- A purchasing agent obtained 60 watt bulbs from two companies. He has the samples tested in his laboratory for the length of the life with the following results: Length of Life (in hours) 1700 and under 1900 1900 and under 2100 2100 and under 2300 2300 and under 2500 2500 and under 2700 Соmpany A Соmpany B 12 3 14 30 20 17 8 6 2 a. Which Company's bulb do you think are better in terms of average life? b. If price of both types are the same, which company's bulbs would you buy and why? ( Coefficient of variation is Mean /Standard deviation **100)arrow_forwardA researcher wants to find the effect of a special diet on systolic blood pressure. A sample of 7 adults was selected to start them on this diet for 3 months. Based on this information, can it be stated that systolic blood pressure changes with the special diet? The test statistic that will determine whether systolic blood pressure changes with the special diet is...... A. 1.23 B. 0.48 C. 18.1 D. 21.08 E. 4.08arrow_forwardIs this correct so far?arrow_forward
- a) Calculate the sample correlation coefficient r (show all your work).b) Calculate the regression line (you may use technology, but you should write up the details).c) Use the regression line obtain in b. to predict the value of y for x = 0.3 year.d) Use the regression line obtain in b. to predict the value of y for x = 0.8 year.arrow_forwardThe table below shows results from a recent General Social Survey on two variables, respondent sex and whether one believes in an afterlife. Compare the proportions of women and men who believe in an afterlife. Question: State the hypotheses, calculate the test statistic, p-value and write your conclusions, using α = 0.05. Belief in Afterlife Sex Yes No or Undecided Total 1. Male 375 134 509 2. Female 435 147 582 Let = 1. be the population proportion of men who believe in an afterlife Let = 2. be the population proportion of women who believe in an afterlifearrow_forwardThe table below summarizes a data set that examines the responses of a random sample of college graduates and non-graduates on the topic of oil drilling. Complete a chi-square test for these data to check whether there is a statistically significant difference in responses from college graduates and non-graduates. That is, H0:H0: The opinion of college grads and nongrads is not different on the topic of drilling for oil and natural gas off the coast of California.HA:HA: Opinions regarding the drilling for oil and natural gas off the coast of California has an association with earning a college degree. Compute the expected counts. If necessary, round to the nearest tenth. College graduates Non-graduates Total Support 154 132 286 Oppose 180 126 306 Do not know 104 131 235 Total 438 389 827 College graduates Non-graduates Total Support 286 Oppose 306 Do not know 235 Total 438 389 827 b) Compute the χ2χ2 test statistic. Round to the nearest…arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill