# Liberty BUSI 230 Week 8 Review and Exam Answers Complete Solutions

It saves a lot of time. You don’t need to solve questions. You would just need to put your values into excel. I put all mathematical formulas. They are the same questions with different values. So easy piece of cake if you just buy this excel solution.

Is the magnitude of an earthquake related to the depth below the surface at which the quake occurs? Let x be the magnitude of an earthquake (on the Richter scale), and let y be the depth (in kilometers) of the quake below the surface at the epicenter.

(a) Make a scatter diagram of the data.

Then visualize the line you think best fits the data.

(b) Use a calculator to verify that Σx = 24.6, Σx2 = 89.86, Σy = 52.6, Σy2 = 444.72 and Σxy = 191.18.

Compute r. (Round to 3 decimal places.)

Answer

As x increases, does the value of r imply that y should tend to increase or decrease? Explain your answer.

In baseball, is there a linear correlation between batting average and home run percentage? Let x represent the batting average of a professional baseball player, and let y represent the player’s home run percentage (number of home runs per 100 times at bat). A random sample of n = 7 professional baseball players gave the following information.

(a) Make a scatter diagram of the data.

Then visualize the line you think best fits the data.

(b) Use a calculator to verify that Σx = 1.957, Σx2 = .553, Σy = 30.3, Σy2 = 152.67 and Σxy = 8.774.

Compute r. (Round to 3 decimal places.)

As x increases, does the value of r imply that y should tend to increase or decrease? Explain your answer.

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).

#### Wait.... Hire Me To Get 100% Original Help In . Watch The Video Below For More Information & How It Works!

## STATUS

Complete parts (a) through (e), given Σx = 97, Σy = 623, Σx2 = 2383, Σy2 = 83,181, Σxy = 13,951, and r ≈ 0.999.

(a) Draw a scatter diagram displaying the data.

(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.)

(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.)

(d) Graph the least-squares line. Be sure to plot the point (x, y) as a point on the line.

(e) Find the value of the coefficient of determination r^2. 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 r^2 to three decimal places. Round your answers for the percentages to one decimal place.)

(f) The calves you want to buy are 16 weeks old. What does the least-squares line predict for a healthy weight? (Round your answer to two decimal places.)

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.

Complete parts (a) through (e), given Σx = 372, Σy = 115, Σx2 = 24814, Σy2 = 3375, Σxy = 8485, and r ≈ 0.947.