A manufacturer produces both a deluxe and a standard model of an
automatic sander designed for home use. Selling prices obtained
from a sample of retail outlets follow.

Model Price
($) 


Model Price
($) 
Retail Outlet 
Deluxe 
Standard 

Retail Outlet 
Deluxe 
Standard 
1 
39 
27 

5 
40 
30 
2 
39 
28 

6 
39 
34 
3 
45 
35 

7 
35 
29 
4 
38 
30 




 The manufacturer's suggested
retail prices for the two models show a $10 price differential. Use
a .05 level of significance and test that the mean difference
between the prices of the two models is $10.
Develop the null and alternative hypotheses.
H _{0} = _{d} Selectgreater
than 10greater than or equal to 10equal to 10less than or equal to
10less than 10not equal to 10Item 1
H _{a} = _{d} Selectgreater
than 10greater than or equal to 10equal to 10less than or equal to
10less than 10not equal to 10Item 2
Calculate the value of the test statistic. If required enter
negative values as negative numbers. (to 2 decimals).
The pvalue is Selectless than .01between .10 and
.05between .05 and .10between .10 and .20between .20 and .40greater
than .40Item 4
Can you conclude that the price differential is not equal to
$10?
SelectYesNoItem 5
 What is the 95% confidence
interval for the difference between the mean prices of the two
models (to 2 decimals)? Use a ttable.
( , )