In Exercises 5–20, assume that the two samples are independent simple random samples selected from
17. Are Male Professors and Female Professors Rated Differently? Listed below are student evaluation scores of female professors and male professors from Data Set 17 “Course Evaluations” in Appendix B. Test the claim that female professors and male professors have the same mean evaluation ratings. Does there appear to be a difference?
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
ESSENTIALS OF STATISTICS 6TH ED W/MYSTA
- The table below shows the estimated vaccination coverage of adolescents aged 13-17 years, as reported in national surveys in 2020 and 2021. Vaccine Percent vaccinated (95% CI) Tdap (tetanus, diphtheria, and acellular pertussis vaccine) 2020: 90.1 (89.2–90.9) 2021: 89.6 (88.6–90.5) MMR (measles, mumps, and rubella vaccine) 2020: 92.4 (91.6–93.2) 2021: 92.2 (91.2–93.2) HPV (human papillomavirus vaccine) 2020: 58.6 (57.3–60.0) 2021: 61.7 (60.2–63.2) Answer these: a. For which vaccine(s) was there a statistically significant change in coverage from 2020 to 2021? For each, note whether it was a statistically significant increase or decrease? b. For which vaccine(s) was there no significant change in coverage from 2020 to 2021?arrow_forwardA clinical psychologist is interested in the relationship between testosterone level in married males and the quality of their marital relationship. A study is conducted in which the testosterone levels of eight married men are measured. The eight men also fill out a standardized questionnaire assessing quality of marital relationship. The questionnaire scale is 0–25, with higher numbers indicating better relationships. Testosterone scores are in nanomoles/liter of serum. The data are shown below. Subject Number 1 2 3 4 5 6 7 8 Relationship Score 24 15 15 10 19 11 20 19 Testosterone Level 12 13 19 25 M 16 15 21 a. Determine the least-squares regression line for predicting relationship score from testosterone level. b. What percentage of the variance in relationship score is accounted for by the regression equation? c. Can we conclude that there is a significant relationship between the testosterone level…arrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 13.8 19.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1554.45; Σxy = 274b) Find the equation of the least-squares line. (Round your answers to two decimal places.) ŷ = + x (c) Find r. Find the coefficient of determination r2. (Round your answers to three decimal places.) r = r2 = d) Test the claim that the population correlation coefficient is positive at the 1% level of significance. (Round your test statistic to three decimal places.) t =arrow_forward
- Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 14.2 17.7 14.4 19.6 20.0 Σx = 15; Σy = 85.9; Σx2 = 55; Σy2 = 1,506.45; Σxy = 271.2 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x = y = b = ŷ = + x (b) Draw a scatter diagram for the data. Plot the least-squares line on your scatter diagram. (c) Find the sample correlation coefficient r and the coefficient of determination r2. (Round your answers to three decimal places.) r = r2 = What percentage of variation in y is explained…arrow_forwardII. Conduct a hypothesis test A research center claims that less than 50% of senior high school students in public schools in the Philippines have accessed the Internet using cellular phones. In a random sample of 100 SHS students, 39% say they have accessed the Internet using cellular phones. At = 0.01, is there enough evidence to support the researcher's claim?arrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 15.8 17.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1,540.45; Σxy = 272 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x = y = b = ŷ = + xarrow_forward
- Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 12.2 17.5 14.4 19.6 20.0 (c) Find the sample correlation coefficient r and the coefficient of determination r2. (Round your answers to three decimal places.) r = ? r2 = ? What percentage of variation in y is explained by the least-squares model? __________ %(Round your answer to one decimal place.) incorrect answers: I submitted this question and was told this is the answer but it is NOT CORRECT. please help !! r=0.800 r2= 0.640 64% ( above answers are incorrect)arrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 12.2 20.9 14.4 19.6 20.0 Σx = 15; Σy = 87.1 ; Σx2 = 55; Σy2 =1577.17; Σxy = 275.6 (a) Draw a scatter diagram. (b) Find the equation of the least-squares line. (Round your answers to two decimal places.) ŷ = + x (c) Find r. Find the coefficient of determination r2. (Round your answers to three decimal places.) r = r2 = Explain what these measures mean in the context of the problem. The correlation coefficient r measures the strength of the linear relationship between a bighorn sheep's age and the mortality rate. The coefficient of determination r2 measures the explained…arrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 12.2 20.9 14.4 19.6 20.0 Σx = 15; Σy = 87.1 ; Σx2 = 55; Σy2 =1577.17; Σxy = 275.6 d) Test the claim that the population correlation coefficient is positive at the 1% level of significance. (Round your test statistic to three decimal places.) t = e) Find or estimate the P-value of the test statistic. P-value > 0.250 0.125 < P-value < 0.250 0.100 < P-value < 0.125 0.075 < P-value < 0.100 0.050 < P-value < 0.075 0.025 < P-value < 0.050 0.010 < P-value < 0.025 0.005 < P-value < 0.010 0.0005 < P-value < 0.005 P-value < 0.0005 Conclusion Reject the…arrow_forward
- Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: 1. 3 4 12.2 17.5 14.4 19.6 20.0 A USE SALT Ex = 15; Ey = 83.7; Ex² = 55; Ey? = 1,446.61; Exy = 268.8 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) y = (b) Draw a scatter diagram for the data. Plot the least-squares line on your scatter diagram. y y 22 22 20 20 18 18 16 16 14 14 12 12arrow_forwardType I and Type I l Errors. In Exercises 29–32, provide statements that identify the type I error and the type II error that correspond to the given claim. (Although conclusions are usually expressed in verbal form, the answers here can be expressed with statements that include symbolic expressions such as p = 0.1. The proportion of people who require no vision correction is less than 0.25.arrow_forwardA researcher is conducting a study to examine the relationship between age and agility. She recruited a sample of 50 participants, ranging in age from 20 – 65 years old, and asked them to perform a series of agility tests. Afterward, participants were given an average agility score, which was then used in a correlation analysis against participant age. The results of the study are as follows [r(50) = -0.97, p < 0.001]. Identify the correct interpretation below. A. There is a non-significant, weak, negative correlation between age and agility, suggest that as age increases, agility decreases B. There is a statistically significant, strong, negative correlation between age and agility, suggesting that as age increases, agility decreases C. There is a non-significant, moderate, positive correlation between age and agility, suggesting that there is no relationship between these two variables D. There is a statistically significant, strong positive correlation between age and…arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill