1. Suppose a restaurant chain has run a major advertising campaign in the hopes of increasing monthly sales. To investigate the effectiveness of this campaign, the chain randomly selected seven restaurants and recorded the monthly sales before and after the advertising. The following data represents these sales figures in thousands of dollars.
|
Restaurant
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
|
After
|
$127
|
$122
|
$145
|
$156
|
$160
|
$134
|
$108
|
|
Before
|
$107
|
$110
|
$143
|
$168
|
$145
|
$125
|
$98
|
If Population 1 is defined as the year 2012 and Population 2 is defined as the year 2011, the 90% confidence interval for the difference in population means is ________. Round values to two decimal places.
A. (0.36, 15.64)
B.(-3.46, 19.46)
C. (3.45, 12.55)
D. (-1.63, 17.63)
2) A telephone company would like to test the hypothesis that the proportion of 18-to 34-year-olds that own a cell phone is less than the proportion of 35-to 49-year-olds. A random sample of 200 18-to 34-year-olds found that 126 owned a smartphone. A random sample of 175 35-to 49-year-olds found that 119 owned a smartphone. If Population 1 is defined as 18-to 34-year-olds and Population 2 is defined as 35-to 49-year-olds, the pooled estimate for the overall proportion is ________. Round to three decimal places.
A. 0.680
B. 0.608
C. 0.653
D. 0.627
3) A telephone company would like to test the hypothesis that the proportion of 18-to 34-year-olds that own a cell phone is less than the proportion of 35-to 49-year-olds. A random sample of 200 18-to 34-year-olds found that 126 owned a smartphone. A random sample of 175 35-to 49-year-olds found that 119 owned a smartphone. If Population 1 is defined as 18-to 34-year-olds and Population 2 is defined as 35-to 49-year-olds, the p-value for this hypothesis test is ________.
A. 0.1025
B. 0.0026
C. 0.0087
D. 0.1562