Question

A particular professor has noticed that the number of people, y, who complain about his attitude is dependent on the number of cups of coffee, x, he drinks. From eight days of tracking he compiled the following data:

People (y)	12	10	9	10	9	5	3	4
Cups of coffee (x)	1	1	2	2	3	4	5	5

Unless otherwise stated, you can round values to two decimal places.

a) Using regression to find a linear equation for ˆyy^. Write in the form: a + bx. Round a and b to three decimal places.

ˆyy^ =     

b) Find the correlation coefficient. Round to three or four decimals.

rr =

c) Does the correlation coefficient indicate a strong linear trend, a weak linear trend, or no linear trend?

• strong linear trend
• weak linear trend
• no linear trend

d) Interpret the meaning of the slope of your formula in the context of the problem



e) Interpret the meaning of the y intercept in the context of the problem



f) Use your model to predict the number of people that will complain about his attitude if he drinks 9 cups of coffee.

    

g) Is the answer to part f reasonable? Why or why not?

Answer 1