Questions Asnwers Algebra 1

4/16/2019 Quiz 7 Question 1 Which of the following would be the scatterplot for the given data? x y 4 21 8 29 8 28 13 40 14 31 19 41 a) 1/7 4/16/2019 Print Test b) c) 2/7 4/16/2019 Print Test d) e) None of the above Question 2 What can be said about the relationship between the explantory variable and the response variable in the following scatterplot? 3/7 4/16/2019 Print Test a) There is a strong negative linear association. b) There is a strong positive linear association. c) There is a weak negative linear association. d) The explanatory variable causes the responses. e) None of the above Question 3 Determine the correlation coefficient for the data shown in this table: x y a) 0.3651 b) 0.5332 c) -0.5332 d) 0.7302 e) -0.7302 f) None of the above 3 23 5 29 10 27 11 41 17 33 17 44 Question 4 Choose the best correlation coefficient for the data shown in this scatterplot: 4/7 4/16/2019 Print Test a) -0.8894 b) 0.4447 c) -0.4447 d) 0.8894 e) -1.5924 Question 5 Which of the following is a true statement? a) The variable that is being predicted in regression analysis is the independent variable. If there is no correlation between the independent and dependent variables, then the value of the b) correlation coefficient must be -1. c) The correlation coefficient r is always between -1 and +1. d) The coefficient of determination can assume negative values. e) A negative correlation indicates that as values of x decrease, values of y will decrease. f) None of the above 5/7 4/16/2019 Print Test Question 6 The decline of salmon fisheries along the Columbia River in Oregon has caused great concern among commercial and recreational fishermen. The paper 'Feeding of Predaceous Fishes on Out-Migrating Juvenile Salmonids in John Day Reservoir, Columbia River' (Trans. Amer. Fisheries Soc. (1991: 405-420)) gave the accompanying data on y = maximum size of salmonids consumed by a northern squaw fish (the most abundant salmonid predator) and x = squawfish length, both in mm. Use the following statistics to give the equation of the least squares regression line. x = 524.940, y = 519.050, sx = 9.329, sy = 11.200, r = 0.9662 a) ŷ = 1.160x − 89.880 b) ŷ = 0.805x + 89.880 c) ŷ = 1.160x + 89.880 d) ŷ = 0.805x − 89.880 e) ŷ = -89.880x + 1.160 f) None of the above Question 7 Suppose that you are given the following results. Find the correlation coefficient of the data. sx = 1.791, sy = 13.400, b = -6.480 a) 0.155 b) -0.433 c) -0.866 d) 0.866 e) -0.155 f) None of the above Question 8 Suppose you find that the correlation coefficient for a set of data is 0.841. What is the coefficient of determination and what does it mean? a) 0.841; This means that 84.1% of the variation of y is explained by the LSRL of y on x. 6/7 4/16/2019 Print Test b) 0.841; This means that we are 84.1% accurate with our prediction of the LSRL equation. c) 0.707; This means that 70.7% of the variation of y is explained by the LSRL of y on x. d) 0.707; This means that we are 70.7% accurate with our prediction of the LSRL equation. e) None of the above Question 9 A real estate agent would like to predict the selling price of a single-family house by predicting the price (in thousands of dollars) based on the square footage (in 100 square feet). If the LSRL for the data is ŷ = 3.8785x + 18.3538, predict the price of a 3000 square foot house (in thousands of dollars). tbl a) 139.709 b) 134.709 c) 248.709 d) 252.709 e) 942.962 f) None of the above Question 10 Select the equation of the least squares line for the data: (27.2, 1.50), (26.0, 3.75), (28.0, .75), (24.8, 7.50), (24.0, 6.75), (22.0, 9.75), (23.2, 7.50). a) ŷ = 1.5206 x − 43.434 b) ŷ = -43.434 − 1.5206x c) ŷ = 43.434 − 1.6727x d) ŷ = 43.434 − 1.5206x e) ŷ = 47.777 − 1.6727x f) None of the above 7/7 4/16/2019 Print Test Quiz 8 Question 1 Which of the following would be the LSRL for the given data? x y a) ŷ= b) ŷ= c) ŷ= d) ŷ= e) None of the above 4 23 6 29 11 27 13 42 17 26 19 41 Question 2 Determine the correlation coefficient for the data shown in this table: a) -0.9352 b) 0.9352 c) 0.8746 d) -0.8746 e) -0.4676 f) None of the above x 1 8 9 12 17 20 y 41 38 28 20 18 14 Question 3 Suppose you have the following data: 1/8 4/16/2019 Print Test x 1 2 3 4 5 6 y 44 37 27 21 22 14 and the LSRL is ŷ = . Find the residual value for x = 1. a) b) c) d) e) None of the above Question 4 Which of the following is the residual plot for the data in the given table? x y 1 13 2 19 3 17 4 31 5 17 6 34 a) 2/8 4/16/2019 Print Test b) c) 3/8 4/16/2019 Print Test d) e) None of the above Question 5 Which of the following residual plots would indicate a good LSRL model? a) 4/8 4/16/2019 Print Test b) c) 5/8 4/16/2019 Print Test d) Question 6 For children between the ages of 18 months and 29 months, there is approximately a linear relationship between height and age. The relationship can be represented by ŷ = 62.72 + 0.65x where y represents height (in centimeters) and x represents age (in months). Joseph is 23.5 months old and is 82 centimeters tall. What is Joseph's residual? a) -34.017 b) 116.017 c) 8.008 d) 77.992 e) 4.008 f) None of the above Question 7 If the LSRL relating the independent variable x and the dependent variable y for a given problem is ŷ = 3x + 5, then an increase of 1 unit in x is associated with an increase of how many units in y? a) 5 b) 0 6/8 4/16/2019 Print Test c) 8 d) 1 e) 3 Question 8 If the correlation between number of children in a family and annual income was close to -1, we could conclude that: a) low incomes cause people to have more children. b) low-income families tend to have more children. c) high incomes cause sterility. d) high-income families tend to have more children. e) high incomes cause people to have more children. Question 9 The following two-way table describes the preferences in movies and fast food restaurants for a random sample of 100 people. McDonalds Iron Man 20 Dispicable Me 11 Harry Potter 5 Taco Bell 11 9 15 Wendy's 9 8 12 What percent of people in the sample like the movie Dispicable Me? a) 36% b) 35% c) 29% d) 32% e) 28% Question 10 The following two-way table describes the preferences in movies and fast food restaurants for a random sample of 100 people. McDonald's Taco Bell Wendy's 7/8