Question

After checking the “straight enough” condition, you find the correlation between a person's blood alcohol content and attention span is found to be r = -0.60. Which must be true?

		Blood alcohol content accounts for 60% of the variability in attention span.
		In general, the higher the higher the blood alcohol content, the longer the person's attention span.
		The line of best fit passes through 60% of the (Blood alcohol content, attention span) data points.
		None of the above

Answer 1

Solution: The correct option is None of the above.

Explanation:

The option "Blood alcohol content accounts for 60% of the variability in attention span." is not correct because the -0.60 is the correlation not the coefficient of determination.

The option "In general, the higher the blood alcohol content, the longer the person's attention span." is not correct because the correlation of -0.60 is the negative correlation, therefore, the higher the blood alcohol content, the lesser the person's attention span.

The option "The line of best fit passes through 60% of the (Blood alcohol content, attention span) data points." is not correct because the correlation does not tell us how best the line fits the data.