AP Chapter 4 Review AP Stats

Desiree is interested to see if students who consume more caffeine tend to study more as well. She randomly selects 20 students at her school and records their caffeine intake (mg) and the number of hours spent studying. What is the equation for the LSRL?

• Caffeine = 2.544 + 0.164(hours)

• Hours = 2.544 + 0.164(Caffeine)

• Caffeine = 0.164 + 2.544(hours)

• Hours = 0.164 + 2.544(Caffeine)

The area under the standard normal curve corresponding to -0.2 < z < 2.03 is

• 0.5581

• 0.5686

• 0.3995

• 0.4100

The scores of the math portion of the SAT are approximately normal with a mean of 510 and a standard deviation of 42. Approximately what percent of students will score higher than 600?

• 0.9838

• 0.0162

• 0.0179

• 0.9821

The life span of ladybugs is approximately normally distributed with a mean of 18 months and a standard deviation of 2.5 months. Only about 5% of ladybuds will have a lifespan outside which interval?

• 15.5 to 23 months

• 15.5 to 20.5 months

• 13 to 23 months

• 10.5 to 25.5 months

Is this a probability distribution?

• No, the sum of p(x) does not equal 1.

• Yes, all p(x) are between 0 and 1.

• No, all p(x) are not between 0 and 1.

• Yes, the sum p(x) is 1.

• A

• B

• C

• D

• E

Is this a probability distribution?

• No

• Yes

The average high temperature in July for a midwest city is 89 degrees. What is the standard deviation if 15% of July's on record for the city have an average high temperature above 91.5 degrees? Assume average temperatures are normally distributed.

• s = 0.060

• s = 16.667

• s = 0.416

• s = 2.404

95% of students who take the AP stats exam need between 186 and 214 minutes to complete it. What is the standard deviation of time students need to finish the exam? Assume times are normally distributed.

• 4.67 minutes

• 14 minutes

• 7 minutes

• 28 minutes

Suppose that the mean of a set of values is 20, and the standard deviation is 3. If each value is increased by 5, what will be the mean and standard deviation of the new set of values?

• mean = 25, sd = 8

• mean = 20, sd = 3

• mean = 20, sd = 8

• mean = 25, sd = 3