Deck 23: Inferences for Regression

Question 1

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis and
Summary statistics are given below.Find a 99% confidence interval for the mean lawn
Quality of all lawns sown with a seed density of 2.5.

Answer 1

B

Question 2

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.A 95% prediction interval for the score of an applicant who has studied
Spanish for 4.4 years was determined to be (65.4, 93.6).Give an interpretation of this
Interval.

Answer 2

E

Question 3

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.A 95% confidence interval for the mean score of all applicants who have
Studied Spanish for 4.6 years was determined to be (75.6, 87.7).Give an interpretation of this
Interval.

Answer 3

C

Question 4

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis is given
Below.A 99% prediction interval for the lawn quality of a lawn sown with a seed density of 1.9 was determined to be (5.3, 78.3).Give an interpretation of this interval.

Question 5

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.

Question 6

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis is given
Below.

Question 7

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis and
Summary statistics are given below.Determine a 99% prediction interval for the lawn quality
Of a lawn sown with a seed density of 2.9.

Question 8

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.A 99% confidence interval for the slope of the regression line was
Determined to be (5.05, 16.76).Give an interpretation of this interval.

Question 9

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.Use the regression analysis and summary statistics given below to find a
95% prediction interval for the score of an applicant who has studied Spanish for 3.1 years.

Question 10

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.Use the regression analysis and summary statistics given below to find a
95% confidence interval for the mean score of all applicants who have studied Spanish for 3.1 years.

Question 11

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis is given
Below.Find a 95% confidence interval for the slope of the regression line.

Question 12

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis is given
Below.A 95% confidence interval for the slope of the regression line was determined to be (-1.51, 10.58).Give an interpretation of this interval.

Question 13

A sample of 33 companies was randomly selected and data collected on the average annual bonus, turnover rate (%), and trust index (measured on a scale of 0 - 100).According to the
Output is shown below, what is the estimated multiple regression model?

Question 14

A grass seed company conducts a study to determine the relationship between the density of seeds planted (in pounds per 500 sq ft) and the quality of the resulting lawn.Eight similar
Plots of land are selected and each is planted with a particular density of seed.One month
Later the quality of each lawn is rated on a scale of 0 to 100.The regression analysis is given
Below.A 99% confidence interval for the mean lawn quality of all lawns sown with a seed
Density of 3.5 was found to be (33.3, 60.8).Give an interpretation of this interval.

Question 15

Applicants for a particular job, which involves extensive travel in Spanish-speaking countries, must take a proficiency test in Spanish.The sample data were obtained in a study
Of the relationship between the numbers of years applicants have studied Spanish and their
Score on the test.Use the regression analysis given below to find a 99% confidence interval
For the slope of the regression line.

Question 16

Selling price and amount spent advertising were entered into a multiple regression to determine what affects flat panel LCD TV sales.Using the output below, calculated F
Statistic to determine the overall significance of the estimated multiple regression model is