To help determine which of two cars had a more comfortable ride, twenty-five people rode in the rear seat of an expensive European car and in the back seat of an expensive American car. Each of the twenty-five rated each of the two rides on a 5-point scale:

5 = extremely comfortable
4 = quite comfortable
3 = neither comfortable nor uncomfortable
2 = quite uncomfortable
1 = extremely uncomfortable
 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

Europ

4

2

5

3

2

5

1

4

4

2

3

4

2

3

2

4

2

4

5

3

4

3

3

5

2

Amer

5

1

4

2

1

3

3

2

2

2

2

3

1

4

1

3

1

3

4

1

2

3

4

2

3

Are the cars different in level of comfort at the .90 confidence level?

 

 

To test the effect of a brand name, a marketing researcher asked 60 people to test two different dishes of ice cream and rate them on a 10-point scale ranging from 1=poor to 10=excellent. One dish was labeled with a name that suggested European sophistication and the other was labeled with a name that suggested domestic and inexpensive. In fact, the two dishes contained identical ice cream.
 

1

2

3

4

-

58

59

60

European

6

9

9

5

-

9

9

7

Domestic

4

7

9

4

-

8

9

9

You don't need to count them; there were 32 positive differences, 12 negative differences, and 16 no differences. Do the names have an effect at the .95 confidence level?

 

 

At the peak of the energy shortage in the 1970's, 150 people were asked to what degree they were concerned about the shortage of gasoline and the shortage of electricity.

4 = very concerned
3 = somewhat concerned
2 = not very concerned
1 = not at all concerned
 

1

2

3

4

-

148

149

150

Gasoline

3

4

4

1

  

4

4

1

Electricity

4

3

4

1

  

3

4

1

You don't need to count them; there were 59 positive differences, 41 negative differences, and 52 no differences. Are the concerns different at the .95 confidence level?