Question

Carlson Mining, Inc. has 12 large pumps that pump water from the mines it operates.
Management has been concerned lately about the amount of money required to
repair malfunctioning pumps. These costs are sums over and above the amounts
spent for routine maintenance. When asked what factors they thought might affect
the mean monthly repair costs, employees suggested the age of the pumps and the
number of hours of operation. The following information was collected.
Choose the relevant Summary Output to answer the questions. Note that the
mean monthly repair costs are in dollars, so when questions ask about repair
costs, make sure that your answers reflect that.
Mean Weekly Hours of Operation over Past Year	Age of Pump at First of Year (months)	Mean Monthly Repair Costs over Past Year
28	80	$1,049
26	48	$1,095
15	27	$882
12	2	$447
16	13	$715
21	55	$542
13	30	$415
21	35	$454
16	36	$495
12	13	$370
18	28	$448
18	49	$509

According to your equation, for every month of age, the mean monthly repair
costs (increase / don't change / decrease) by ___________. Round appropriately
and include the units.
What is the standard error of the estimate? Round appropriately and include the
units.
Are the mean monthly repair costs statistically related to the age of the pumps at
the .10 level of significance?
• State H0 and H1.(3 pts.)

Answer 1

The regression output is as follows

Question (1)

The regression equation is

Mean Monthly Repair costs = -87.7004 + 45.0973 * Mean Hours of Operations + (-3.0471) * Age of Pump

For every month of age, Mean monthly repair cost would decrease by 3.0471 $

Question (2)

The Standard error of the esimate can be found from the Regression statistic section of the Summary output in the attached image

So the Standard error of the estimate = 196.9508

Question (3)

Null Hypothesis Ho : 2 = 0 implies mean monthly repair costs statistically is not related to the age of the pumps

Alternate Hypothesis Ho : 2 0 implies mean monthly repair costs statistically is related to the age of the pumps

The p-value for Age of pumps is 0.5815 which is more than the significance level of 0,1

If the p-value is more than the Significance level, we fail to reject the Null Nhypothesis

So mean monthly repair costs statistically is not related to the age of the pumps at a significance level of 0.1