Stats Distribution

What is the standard deviation for the data given:

• 6.89

• 10.1

• 7.26

• 9

This data is normally distributed.  What percent of the data is in the shaded region?

• 68%

• 95%

• 99.7%

• 50%

What does this symbol represent?

• Standard Deviation

• Variance

• Mean Absolute Deviation

• Sigma

The mean life of a tire is 30,000 km. The standard deviation is 2000 km.

Then, 68% of all tires will have a life between ___________ km and __________ km.

•  28,000 km and 32,000 km.

• 24,000 km and 34,000 km.

• 26,000 km and 34,000 km.

• 27,000 km and 31,000 km.

The average waist size for teenage males is 29 inches with a standard deviation of 2 inches. 
If waist sizes are normally distributed, determine the z-score of a teenage male with a 33 inch waist.  

• 2

• 1

• -2

• -1

The mean temperature in Glens Falls for the month of February is 23 degrees with a standard deviation of 4.2 degrees.  What is the z-score for a temperature of 17 degrees?  

• 1 

• 1.43

• -1.43

• 11.5

Find the area of the shaded region. 

• 0.16

• 0.84

• 0.68

• 0.34

The caffeine content of 8-ounce cans of a certain cola drink is approximately normally distributed with mean 33 milligrams (mg). A randomly selected 8-ounce can containing 35 mg of caffeine is 1.2 standard deviations above the mean. Approximately what percent of 8-ounce cans of the cola have a caffeine content greater than 35 mg?

• 1%

• 8%

• 12%

• 16%

• 99%

The weight of adult male grizzly bears living in the continental US is approximately normally distributed with a mean of 500 pounds and a standard deviation of 50 pounds. The weight of adult female grizzly bears is approximately normally distributed with a mean of 300 pounds and a standard deviation of 40 pounds. Approximately, what would be the weight of a female grizzly bear with the same standardized score (z-score) as a male grizzly bear with a weight of 530 pounds?

• 276 pounds

• 324 pounds

• 330 pounds

• 342 pounds

• 533 pounds

A certain type of remote-control car has a fully charged battery at the time of purchase. The distribution of running times of cars of this type, before they require recharging of the battery for the first time after its period of initial use, is approximately normal with a mean of 80 minutes and a standard deviation of 2.5 minutes. The shaded area in the figure below represents which of the following probabilities? The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is

• between 75 minutes and 82.5 minutes.

• between 75 minutes and 85 minutes.

• between 77.5 minutes and 82.5 minutes.

• between 77.5 minutes and 85 minutes.

• 77.5 minutes and 87.5 minutes.