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
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
Essentials of Statistics (6th Edition)
- A 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_forwardA relationship expert wants to know if people with higher levels of emotional intelligence (measured on an interval scale from 1–6, with higher numbers meaning more intelligence) will be better liked upon first meeting people (measured on a 1–5 interval scale, with higher numbers meaning more likable). X: Emotional Intelligence Score X: First Impression Rating 6 1 2.5 4 M=3.38 s=2.14 SS = 13.69 Y: First Impression Rating 5 1.5 3 3.5 M=3.25 s=1.44 SS = 6.25 a) Create a scatterplot of the data. b) Calculate r and r2 . c) Report results in APA style. d) What do the results mean?arrow_forwardA relationship expert wants to know if people with higher levels of emotionalintelligence (measured on an interval scale from 1–6, with higher numbers meaning more intelligence) will be better liked upon first meeting people (measured on a 1–5 interval scale, with higher numbers meaning more likable). X: Emotional Intelligence Score Y: First Impression Rating 6 4.5 2.5 3.2 3 3 1 2 M=3.13s=2.10SS = 13.19 M=3.18s=1.03SS = 3.17 c) Report results in APA style.d) What do the results mean?arrow_forward
- A relationship expert wants to know if people with higher levels of emotionalintelligence (measured on an interval scale from 1–6, with higher numbers meaning more intelligence) will be better liked upon first meeting people (measured on a 1–5 interval scale, with higher numbers meaning more likable). X: Emotional Intelligence Score Y: First Impression Rating 6 4.5 3 3.2 2.5 3 1 2 M=3.13s=2.10SS = 13.19 M=3.18s=1.03SS = 3.17 a) Create a scatterplot of the data.b) Calculate r and r2 .c) Report results in APA style.d) What do the results mean?arrow_forwardA manufacturer knows that their items lifespans are normally distributed according to N(5.1,1.5)N(5.1,1.5).What proportion of the items' lifespans will be longer than 6 years?arrow_forwardLet X₁, X2,..., be a sequence of independent and identically distributed random variables, each with a mean value x and variance ok, both of which are assumed to be finite. Let N be a discrete random variable independent of X₁, X2,..., and assuming values in the set {0, 1, 2, ...}, with mean value N and variance ok (both are finite). Form the random-compound sum Y=1 Xk, with the convention Y = 0 whenever N = 0.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 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_forwardFind the z score for test scores of 70 _____ and 90 ______.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 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_forward
- I. 6) Suppose that you score 79 on Exam 3. If the average score is 85, and the variance is 23.04, your z-score is: a) 0.26 b) -0.26 c) 1.25 d) -1.25 e) -2.05arrow_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_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 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_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman