Homework 3A
The Quick Sell Car Dealership has been using 1-minute spot ads on a local TV station. The ads always occur during the evening hours and describe the different models and price ranges of cars on the lot that week. During a 10-week period, the
Quick Sell dealer kept a weekly record of the number of TV ads versus the number of cars sold. You want to predict the number of cars sold based on the number of ads. Number of TV Number of
Ads                   Cars Sold
4                            15
15                         23
2                            18
10                         20
20                         24
20                         18
14                            18
21                            24
8                            12
2                            18
a. If a lower number of ads results in fewer cars sold, the slope of the line plotting the number of ads versus number of cars sold should be (positive / zero / negative.) Choose one. (1 pt.)
b. Determine whether the relationship between the number of TV ads and the number of cars sold is linear. Construct the appropriate chart. Use the number of ads to predict the number of cars sold. (3 pts.)
C. How much of the variability in the number of cars sold is explained by the number of TV ads? (This should be a whole number percentage.) (1 pt.)
d. Write the linear regression equation to predict the number of cars sold based on the number of TV ads. (1 pt.)
e. The manager decided that Quick Sell can afford only 5 ads per week. At that level of advertisement, how many cars can Quick Sell expect to sell each week?
(1 pt.) Round appropriately and don't forget the units.
f. According to your regression equation, for every additional TV ad, the number of cars sold (increases / does not change / decreases) by
(Fill in the blank with a number.) Round appropriately and include the units!
g. If the Quick sale car dealership wants to sell 20 cars, how many TV ads should they buy? (1 pt.) Round appropriately and don't forget the units.
h. Is the number of cars sold statistically related to the number of TV ads? Test at the .05 level of significance:
State H and H1. (1 pt.)
Show your output. (1 pt.)
What is your pvalue? (1 pt.)
Did you reject or not reject Ho? (1 pt.)
At the .05 level of significance, the number of cars sold (is / is not ) statistically related to the number of TV ads. (1 pt.)
i. According to the results of your hypothesis test at the .05 level of significance, if Quick Sell increases the number of TV ads they run, will they sell more cars? Yes No Defend your answer. (1 pt.)
j. Describe the relationship between the two variables. (Hint: There are 3 things you should mention in your description.) (3 pts.)

Homework 3A The Quick Sell Car Dealership has been using 1-minute...