EOS: Probability and Statistics Review

Marcus's music store sells CDs with a mean of 455 and a standard deviation of 65. What did Carlos find about this sales pattern?

• Carlos found a 68% chance that fewer than 390 CDs are sold in a week.

• Carlos found a 34% chance that fewer than 390 CDs are sold in a week.

• Carlos found an 84% chance that more than 390 CDs are sold in a week.

What was the percentage of female students in the 18–24 age group in a university?

• 53.28%

• 58.44%

Marcus and two students conducted an experiment to understand the relationship between the height a parasail can reach and the speed of the motorboat towing it. Which equation represents the height of the parasail (y) based on the speed of the motorboat (x)?

• y = 2.5x – 26.25

• y = 0.4x

• y = 2.5x

The graphs show the air humidity levels in Los Angeles for a week.

Which of the following regression lines would result in the smallest sum of the residuals?

• 
• 
• 

Keisha is a swimmer. The table shows her 100-meter freestyle times over six years. Sketch a scatter plot and determine the closest correlation coefficient.

• 0.20

• 0.99

• -0.20

Which statement is true?

• Correlation proves causation.

• Causation requires correlation.

• Correlation implies causation.

How many distinct license plates can be created in New York if a standard plate has 3 letters followed by 4 numbers, with repetition allowed?

Carlos has calculated the probability of an event A and the probability of neither event A nor B occurring. Can Marcus figure out the probability of event B?

• 0.8

• 0.2

• 0.6

A company makes 70% of the phones with a touch screen and 55% with HD movie capability. 30% of the phones have both. What is the probability that a randomly chosen phone has either a touch screen or HD movie capability?

What is the probability that all five fair coins land heads?

• 1/32

• 1/64

• 5/5