Statistics_Chapter 6 Review

Find the area under the normal distribution curve between 
z=-1.53 and z=0.

• 0.437
• 0.563
• 0.500
• 0.063

What is the total area under the normal curve in a standard normal distribution?

• 1

• 2

• 3

• 4

If Gonzalo's score is 87, the class average is 82, and the SD is 4, what is Gonzalo's Z-score?

• -1.25
• +1.25
• +1.20
• +1.02

Tags

CCSS.HSS.ID.A.4

A trucking firm determines that its fleet of trucks averages a mean of 12.4 miles per gallon with a standard deviation of 1.2 miles per gallon on cross-country hauls. What is the probability that one of the trucks averages fewer than 10 miles per gallon? Assume the distribution is normal.

• 0.0082
• 0.0228
• 0.4772
• 0.5228

A factory dumps an average of 2.43 tons of pollutants into a river every week. If the standard deviation is 0.88 tons, what is the probability that in a week more than 3 tons are dumped?

• 0.2578
• 0.2843
• 0.6500
• 0.7157

An electronic product takes an average of 3.4 hours to move through an assembly line. If the standard deviation is 0.5 hour, what is the probability that an item will take between 3 and 4 hours?

• 0.2119
• 0.2295
• 0.3270
• 0.6730

Find the value of z such that 0.6318 of the area lies between -z and z. Round your answer to two decimal places.

• z = 0.90

• z = -0.90

• z = 1.28

• z = -1.28

Suppose ACT Reading scores are normally distributed with a mean of 21.6 and a standard deviation of 6.3. A university plans to award scholarships to students whose scores are in the top 9%. What is the minimum score required for the scholarship? Round your answer to the nearest tenth, if necessary

• 30

• 26

• 34

• 38

A soft drink machine outputs a mean of 28 ounces per cup. The machine's output is normally distributed with a standard deviation of 2 ounces. What is the probability of filling a cup between 26 and 31 ounces? Round your answer to four decimal places.

• 0.7745

• 0.9332

• 0.1587

• 0.6825

The diameters of ball bearings are normally distributed. The mean diameter is 101 millimeters and the standard deviation is 2 millimeters. Find the probability that the diameter of a selected bearing is greater than 104 millimeters. Round your answer to four decimal places.

• 0.0668

• 0.9332

• 0.2607

• 0.4952