Question

1. A researcher conducts a survey to determine the relationship between aptitude for mathematics and musical ability. She finds a perfect relationship. High levels of mathematics aptitude are associated with low levels of musical ability. Given this information, what is the value of the correlation coefficient for the above study? ______________

2. You obtain a score of 80 on a test. If the test is graded on a ‘curve’ (based on how you did in comparison with the class as a whole), in which of the following classes would you rather be?

a) Mean =75 S=4   b) Mean =65 S=2   c) Mean =70 S=10   d) Mean =65 S=5

3. In any normal distribution, the mean, mode and median will all have the same value.

a) true    b) false

4. Given a normally distributed variable with a m =50 and s=7

a) What would be the value of a score that is one standard deviation below the mean?

                               

b) What is the z-score of 71?                                

5. A college conducts research to determine the correlation between college entrance examination grades and GPA. The correlation was found to be 1.23. On the basis of this information, you conclude:

a) the exam is a good indicator of success in college

b) the exam is a poor indicator of success in college

c) those who do be on the exam make the poorest students

d) the college should hire a new statistician

6. The z distribution has a mean of               , and a standard deviation of                 .

7. A perfect positive correlation is found between scores on a test of ESP ability and income. From this information, it is possible to conclude that ESP ability causes people to make better business decisions and obtain a higher income.

a) true       b) false

8. After several studies, Prof. Jones concludes that there is a negative relationship between oil prices and the price of furniture. This means that:

a) high oil prices are associated with high furniture prices

b) low oil prices have no relationship to furniture prices

c) low oil prices are associated with high furniture prices

            d) the price of oil causes changes in the price of furniture

9. Transformations from z scores to other types of standard scores

a) change the shape of the original distribution but not the relative standing of any test scores within the distribution.

b) change the relative standing of any test score within the original distribution, but not the shape of the distribution

c) change both the shape of the original distribution and the relative standing of any test score within the distribution.

d) change neither the shape of the original distribution nor the relative standing of any test score within the distribution

10. The SXY means that SX is multiplied by the SY.

a) true      b) false

11. .   Frequency polygons and histograms are used to display

            a) qualitative data

            b) quantitative data

            c) both qualitative and quantitative data

            d) neither qualitative or quantitative data

12. Which correlation coefficient shows the weakest degree of relationship between two variables?

a) .75               b) .-33             c) -.95              d) .15

13. What does the following scatterplot suggest:

1. a strong positive relationship between X and Y
2. a weak positive relationship between X and Y
3. a strong negative relationship between X and Y
4. a weak negative relationship between X and Y
5. no relationship between X and Y

Answer 1

1)

r = -1 , for perfect negative relationship

..............

3)

In any normal distribution, the mean, mode and median will all have the same value.

a) true

.................

4)

m=50

s =7

x = 50- 7

=43

.....

b)

Z=(X-µ)/σ=   (71-50)/7)=       3
...........

5)

d) the college should hire a new statistician

..............

6)

mean = 0

std dev= 1

...........

7)

TRUE

............

8)

c) low oil prices are associated with high furniture prices

..................

Please revert back in case of any doubt.

Please upvote. Thanks in advance.