Question

QUESTION 1

When x is 2, y is 5. When x is 4, y is 1. The correlation coeficient will be

	a.	positive in value
	b.	negative in value
	c.	zero

QUESTION 2

The association between the variables "airfare" and "distance to destination" would be

	a.	POSITIVE
	b.	NEGATIVE
	c.	NEITHER

QUESTION 3

The association between the variables "dollars earned" and "hours worked" for a worker at store would be

	a.	POSITIVE
	b.	NEGATIVE
	c.	NEITHER

QUESTION 4

What is the minimum value of the correlation that will be accepted in this course as evidence of a linear relationship?

	a.	0.25
	b.	0.75
	c.	0.80
	d.	0.99

QUESTION 5

The association between the variables "lifetime of a forest fire" and "number of trees alive in the forest" would be

	a.	POSITIVE
	b.	NEGATIVE
	c.	NEITHER

Answer 1

QUESTION 1

When x is 2, y is 5. When x is 4, y is 1. The correlation coeficient will be

	a.	positive in value
	b.	negative in value
	c.	zero

If we look at the value of 'x' it increase from 2 to 4. Accordingly the value of 'y' decrease from 5 to 1. This shows an inverse relationship between the variables x and y. This is denoted by the negative correlation.

QUESTION 2

The association between the variables "airfare" and "distance to destination" would be

	a.	POSITIVE
	b.	NEGATIVE
	c.	NEITHER

The airfare depends upon the distance to destination. The further the destination the higher will be the airfares and vice verse. They have a direct relationship.

QUESTION 3

The association between the variables "dollars earned" and "hours worked" for a worker at store would be

	a.	POSITIVE
	b.	NEGATIVE
	c.	NEITHER

This will be positive since the more you work the more money you could earn. Hence they to share a direct relationship.

QUESTION 4

What is the minimum value of the correlation that will be accepted in this course as evidence of a linear relationship?

	a.	0.25
	b.	0.75
	c.	0.80
	d.	0.99

Generally a value of correlation coefficient less than +0.8 or -0.8 is considered weak or no relationship. Hence a minimum of 0.80 would be needed to conclude that there is linear relationship.

QUESTION 5

The association between the variables "lifetime of a forest fire" and "number of trees alive in the forest" would be

	a.	POSITIVE
	b.	NEGATIVE
	c.	NEITHER

There is negative relation because the longer the fire stays there is more danger to the trees and more trees are likely to die. Therefore increase in the lifetime of forest fire will decrease the number of lives alive in the forest.