A university would like to describe the relationship between the GPA and the starting monthly salary of a graduate who earned a business degree from the university. The table shown below gives the monthly starting salaries for five graduates of the business school along with their corresponding GPAs. These data have a sample correlation coefficient, rounded to three decimal places, of 0.928. Using α=0.05, test if the population correlation coefficient between the starting salary and the GPA of a university business graduate is greater than zero.
Starting Salary GPA
2,600 3.1
3,000 3.5
2,500 2.6
2,900 3.7
2,300 2.6
a.) What are the correct null and alternative hypotheses?
b. test statistic
c. p value
d. state the conclusion
The following table shows the hot dogs bought from a street vendor over the course of eight days ("Demand"). Also shown is the temperature for each day in degrees Celsius. Complete parts a and b below.
Temperature Demand
20 49
12 28
23 36
17 39
9 16
12 22
17 42
21 31
a. Calculate the slope and y-intercept for the linear regression equation for these data. (two decimal places)
b. Predict the demand for hot dogs on a day with a temperature of 14 degrees Celsius.
An electronics retailer would like to investigate the relationship between the selling price of a digital camera and the demand for it. The table shown below gives the weekly demand for the camera in one particular market along with the corresponding price. These data have a sample correlation coefficient, rounded to three decimal places, of -0.839. Using α=0.10, test if the population correlation coefficient between the selling price and the demand for the camera is less than zero. What conclusions can you draw?
Demand Price
15 350
19 360
15 370
10 380
7 390
a.) What are the correct null and alternative hypotheses?
b. test statistic
c. p value
d. state the conclusion