It is thought that basketball teams that make too many fouls in a game tend to lose the game even if they otherwise play well. Let x be the number of fouls more than (i.e., over and above) the opposing team. Let y be the percentage of times the team with the larger number of fouls wins the game. x 1 2 5 6 y 48 42 33 26 Complete parts (a) through (e), given Σx = 14, Σy = 149, Σx2 = 66, Σy2 = 5833, Σxy = 453, and r ≈ −0.988. (a) Draw a scatter diagram displaying the data. Get Flash Player Flash Player version 10 or higher is required for this question. You can get Flash Player free from Adobe's website. (b) Verify the given sums Σx, Σy, Σx2, Σy2, Σxy, and the value of the sample correlation coefficient r. (Round your value for r to three decimal places.) Σx = Σy = Σx2 = Σy2 = Σxy = r = (c) Find x, and y. Then find the equation of the least-squares line y hat = a + bx. (Round your answers for x and y to two decimal places. Round your answers for a and b to three decimal places.) x = y = y hat = + x (d) Graph the least-squares line. Be sure to plot the point (x, y) as a point on the line. WebAssign Plot WebAssign Plot WebAssign Plot WebAssign Plot (e) Find the value of the coefficient of determination r2. What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (Round your answer for r2 to three decimal places. Round your answers for the percentages to one decimal place.) r2 = explained % unexplained % (f) If a team had x = 4 fouls over and above the opposing team, what does the least-squares equation forecast for y? (Round your answer to two decimal places.) %
X | Y | X * Y | |||
1 | 48 | 48 | 1 | 2304 | |
2 | 42 | 84 | 4 | 1764 | |
5 | 33 | 165 | 25 | 1089 | |
6 | 26 | 156 | 36 | 676 | |
Total | 14 | 149 | 453 | 66 | 5833 |
r = -0.988
Equation of regression line is
b = -4.029
a =( 149 - ( -4.0294 * 14 ) ) / 4
a = 51.353
Equation of regression line becomes
Coefficient of Determination
Explained variation = 0.976* 100 = 97.6%
Unexplained variation = 1 - 0.976* 100 = 2.4%
When X = 4
= 51.353 +
-4.029 X
= 51.353 +
-4.029 * 4
=
35.24
It is thought that basketball teams that make too many fouls in a game tend to lose the game even if they otherwise play well. Let x be the number of fouls more than (i.e., over and above) the opposin...
Let x be per capita income in thousands of dollars. Let y be the number of medical doctors per 10,000 residents. Six small cities in Oregon gave the following information about x and y. x 8.2 9.7 10.0 8.0 8.3 8.7 y 9.5 18.7 20.2 10.2 11.4 13.1 Complete parts (a) through (e), given Σx = 52.9, Σy = 83.1, Σx2 = 469.91, Σy2 = 1253.59, Σxy = 751.48, and r ≈ 0.991. (a) Draw a scatter diagram displaying the...
It is thought that basketball teams that make too many fouls in a game tend to lose the game even if they otherwise play well. Let x be the number of fouls more than (i.e., over and above) the opposing team. Let y be the percentage of times the team with the larger number of fouls wins the game. х 33 26 y48 44 14, Ey 151, x2 = 66, Ey2 = 6005, Exy Complete parts (a) through (e), given...
Do heavier cars really use more gasoline? Suppose a car is chosen at random. Let x be the weight of the car (in hundreds of pounds), and let y be the miles per gallon (mpg). x 29 44 33 47 23 40 34 52 y 32 20 26 13 29 17 21 14 Complete parts (a) through (e), given Σx = 302, Σy = 172, Σx2 = 12,064, Σy2 = 4036, Σxy = 6066, and r ≈ −0.902. (a) Draw...
Do heavier cars really use more gasoline? Suppose a car is chosen at random. Let x be the weight of the car (in hundreds of pounds), and let y be the miles per gallon (mpg). x 30 43 31 47 23 40 34 52 y 30 21 22 13 29 17 21 14 Complete parts (a) through (e), given Σx = 300, Σy = 167, Σx2 = 11,908, Σy2 = 3761, Σxy = 5885, and r ≈ −0.888. (a) Draw...
Let x be the age of a licensed driver in years. Let y be the percentage of all fatal accidents (for a given age) due to failure to yield the right of way. For example, the first data pair states that 5% of all fatal accidents of 37-year-olds are due to failure to yield the right of way. x 37 47 57 67 77 87 y 5 8 10 17 33 42 Complete parts (a) through (e), given Σx =...
You are the foreman of the Bar-S cattle ranch in Colorado. A neighboring ranch has calves for sale, and you are going to buy some calves to add to the Bar-S herd. How much should a healthy calf weigh? Let x be the age of the calf (in weeks), and let y be the weight of the calf (in kilograms). x 3 4 8 16 26 36 y 45 53 75 100 150 200 Complete parts (a) through (e), given...
Let x be the percentage of 16- to 19-year-olds not in school and not high school graduates. Let y be the reported violent crimes per 1000 residents. Six small cities in Arkansas (Blytheville, El Dorado, Hot Springs, Jonesboro, Rogers, and Russellville) reported the following information about x and y. x 24.5 19.0 18.5 14.9 19.0 17.5 y 12.9 4.8 8.6 1.3 0.8 3.6 Complete parts (a) through (e), given Σx = 113.4, Σy = 32, Σx2 = 2192.76, Σy2 =...
1. Suppose you are interested in buying a new Lincoln Navigator or Town Car. You are standing on the sales lot looking at a model with different options. The list price is on the vehicle. As a salesperson approaches, you wonder what the dealer invoice price is for this model with its options. The following data are based on a random selection of these cars of different models and options. Let y be the dealer invoice (in thousands of dollars)...
Let x be the average number of employees in a group health insurance plan, and let y be the average administrative cost as a percentage of claims. x 3 7 15 32 70 y 40 35 30 26 18 Use a calculator to verify that Σx = 127, Σx2 = 6207, Σy = 149, Σy2 = 4725, and Σxy = 2907. Compute r. (Round your answer to three decimal places.) r = 3
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 15.4 19.3 14.4...