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?
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Essentials of Statistics (6th Edition)
- The article cited in Exercise 4 also investigated the effects of the factors on glucose consumption (in g/L). A single measurement is provided for each combination of factors (in the article, there was some replication). The results are presented in the following table. Glucose Consumption 68.0 -1 -1 -1 -1 -1 77.5 -1 -1 98.0 1. 1. -1 98.0 -1 -1 74.0 -1 77.0 -1 97.0 98.0 Compute estimates of the main effects and the interactions. a. Is it possible to compute an error sum of squares? Explain. Are any of the interactions among the larger effects? If so, which ones? d. Assume that it is known from past experience that the additive model holds. Add the sums of squares for the interactions, and use that result in place of an error sum of squares to test the hypotheses that the main effects are equal to 0. Ъ. C.arrow_forwardExercises 1–5 refer to the sample data in the following table, which summarizes the last digits of the heights (cm) of 300 randomly selected subjects (from Data Set 1 “Body Data” in Appendix B). Assume that we want to use a 0.05 significance level to test the claim that the data are from a population having the property that the last digits are all equally likely. If using a 0.05 significance level to test the stated claim, find the number of degrees of freedom.arrow_forwardScientists conducting a study on global climate change want to determine if there has been an increase in the number of days per year that the temperature in El Paso rises above 100 degrees Fahrenheit. In 1981, there were 21 days where the temperature rose above 100 degrees Fahrenheit. The scientists want to know whether the average number of days per year that the temperature rises above 100 degrees Fahrenheit has increased. Which hypothesis test would be most appropriate for this study? O One mean (sigma known) - one sample z O One mean (sigma unknown) - one sample t O Mean of differences, using dependent samples (paired data) O Difference of two means (independent samples) O Several means (ANOVA) O One proportion O Difference of two proportions O Chi-Squared test for independencearrow_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_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_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_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 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_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_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 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_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