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

Are mean monthly repair costs statistically related to the age of the pumps? Test
at the .10 level of significance:
•   What is your pvalue?
•   Did you reject or not reject H0?
•   The mean monthly repair costs (are / are not) statistically related to the age of
the pumps.
Is the intercept term significant at the .10 level of significance?   Yes   No

Answer 1

Excel:

Data --> Data analysis --> Regression

	Coefficients	Standard Error	t Stat	P-value
Intercept	-87.70037103	261.5249413	-0.33534	0.745051
Mean Weekly Hours of Operation over Past Year	45.09732343	21.8704701	2.062019	0.069253
Age of Pump at First of Year (months)	-3.047157232	5.329493207	-0.57175	0.581485

What is your pvalue?

Ans : 0.581485

Did you reject or not reject H₀?

Do not reject H0, since P-value > 0.10

The mean monthly repair costs (are / are not) statistically related to the age of the pumps?

Ans : Not related

Is the intercept term significant at the .10 level of significance?   Yes   No

Ans : NO, since P-value = 0.745051 >0.10