Question

1) If the standard deviation is of a distribution is 10, the variance for the distribution is

A. Half the value of the standard deviation or 5 B.  The standard deviation squared or 100

2) What type of variable would represent number of pounds lost?

A. Ratio. B. Interval

3) If half the variance of a distribution is 50, what is ¼ the standard deviation of the distribution?
A 10. B. 2.5

4) Combined, a bat and a ball cost $1.10, the bat costs $1.00 more than the ball, what does the ball cost?

A. 1.00. B. 0.05

5) Which of the following classic sayings describes a “negative” correlation?

A. “The bigger they are, the harder they fall”. B. Good things come in small packages”

6) Which of the following describes the absence of any correlation or a very low correlation?

A The bigger they are, the harder they fall” B. You can’t judge a book by its cover”

7) You come across the following three correlations. A. r = -0.75, B. r = .58, C. r = -0.32
Which of the following is NOT true?

A. A is stronger than B and B is stronger than C. B. Correlations A and C are negative and correlation B is positive

8) Correlation

A. The weakest correlation is -1.0 or +1.0 B. Does not imply causation

  

  

Answer 1

1) If the standard deviation is of a distribution is 10, the variance for the distribution is

Answer)

Variance = square of standard deviation = 10^2 = 100

2)

Ratio

As in ratio difference in between two values is meaningful and also 0 means a point

10 pound = half of 20 pound

So answer is ratio

3) If half the variance of a distribution is 50, what is ¼ the standard deviation of the distribution?

Answer)

Variance = 50*2 = 100

Standard deviation = √variance = 10

10/4 = 2.5

4) Combined, a bat and a ball cost $1.10, the bat costs $1.00 more than the ball, what does the ball cost?

Answer)

Let the cost of the bat be x then the cost of the ball would be x - 1

So,x + x - 1 = 1.1

X = 1.05

So, ball costs 1.1 - 1.05 = 0.05