Question

A. 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	33	70
y	40	35	30	27	17

Make a scatter diagram of the data and visualize the line you think best fits the data.Use a calculator to verify that Σx = 128, Σx² = 6272, Σy = 149, Σy² = 4743, and Σxy = 2896.

Compute r. (Round your answer to three decimal places.)
r =  

B. Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents.

x	10.5	28.2	24.5	14.3	7.5	27.7	16.2	20.1
y	27	78	39	23	15	30	15	25

Make a scatter diagram of the data.

Use a calculator to verify that Σx = 149.0, Σx² = 3200.22, Σy = 252, Σy² = 10838 and Σxy = 5456.5.

Compute r. (Round to 3 decimal places.)

Answer 1

a) Scatter Plot:

Correlation Coefficient :

Answer: rxy = -0.964

b) Scatter plot:

Correlation Coefficient :

Answer : rxy =- 0.687