Question

1. One hundred percent of scores fall under the area of the normal curve.

true

false

2. A z score tells nothing about the distance of a score from the mean.

true

false

3. A z score does NOT allow for the comparison of different scores from different distributions

true

false

4. A number whose z score is equal to zero is equal to the mean.

true

false

5. Which of the following is not a characteristic of the normal distribution?

a. It is symmetrical around the mean

b. It is unimodal

c. Fifty percent of all cases fall within one standard deviation from the mean

d. A set percentage of cases fall within a given standard deviation from mean

6. Given the following data, convert the raw score into a z-score: x=36, mean=30, sd=2

a. 2.4

b. 3.0

c. 2.0

d. 1.5

7. A normal curve:

a. is a theoretical ideal or model.

b. can be used to describe distributions.

c. is used in statistics for making decisions.

d. all of the above are true of the normal curve.

8. Roughly __________ of the total area under the normal curve rests between two standard deviations above and below the mean.

a. 68%

b. 47%

c. 99%

d. 95%

9. The average price for a new car is $18,000 and the standard deviation is $1,500. Calculate the z scores for the following individual scores. SHOW YOUR WORK.If X = 16,000, z =

Answer 1

1)TRUE

2)FALSE

3)FALSE

4)TRUE

5)wrong option is,

c. Fifty percent of all cases fall within one standard deviation from the mean.

6)z score is=(x-mean)/sd

from given, z score = (36-30)/2

=3

answer is, b. 3.0

7)since, all the statements about normal curve are trye

answer is. d. all of the above are true of the normal curve.

8)Roughly 95% of the total area under the normal curve rests between two standard deviations above and below the mean.

answer is, d. 95%

9)

z score is=(x-mean)/sd

from given, z score = (16000-18000)/1500

=-1.333

​​​​​​​answer is -1.333