Bardi Trucking Company, located in Cleveland, Ohio, makes deliveries in the Great Lakes region, the Southeast, and the Northeast. Jim Bardi, the president, is studying the relationship between the distance a shipment must travel and the length of time, in days, it takes the shipment to arrive at its destination. To investigate, Mr. Bardi selected a random sample of 20 shipments made last month. Shipping distance is the independent variable and shipping time is the dependent variable. The results are as follows:
Shipment Distance (miles) Shipping Time (days) Shipment Distance (miles) Shipping Time (days)
1 656 5 11 862 7
2 853 14 12 679 5
3 646 6 13 835 13
4 783 11 14 607 3
5 610 8 15 665 8
6 841 10 16 647 7
7 785 9 17 685 10
8 639 9 18 720 8
9 762 10 19 652 6
10 762 9 20 828 10
a. Draw a scatter diagram. Based on these data, does it appear that there is a relationship between how many miles a shipment has to go and the time it takes to arrive at its destination?
1. On the graph below, use the point tool to plot the point corresponding to the first Distance and its Shipping Time (Distance 1).
2. Repeat the process for the remainder of the sample (Distance 2, Distance 3, … ).
3. To enter exact coordinates, double-click on the point and enter the exact coordinates of x and y.
b-1. Are distance and days positively correlated? What are the null and alternate hypotheses?
b-2. Using a 0.05 significance level, what is the test statistics? (Round your answer to 4 decimal places.
b-3. What is the p-value for the hypothesis test? (Round your answer to 4 decimal places.)
b-4. Using a 0.05 significance level, what is your decision regarding the null hypotheses?
b-5. At the 0.05 significance level, can we conclude that there is a positive correlation between distance and time?
c-1. Determine the coefficient of determination. (Round your answer to 4 decimal places.)
c-2. Fill in the blank below. (Round your answer to 2 decimal places.)
d. Determine the standard error of estimate. (Round your answer to 4 decimal places.)
e. Would you recommend using the regression equation to accurately predict shipping time?
