Normal Probability Curve

1.  Which best describes the shaded part of this normal distribution graph?  

• All data that is one or higher.
• All data that is one or more standard deviations above the mean.
• All data that is between 1 and 3.
• All data that is above the mean.

Between what two standard deviations of a normal distribution contain 68% of the data?

• one below and one above
• two below and two above
• two below and zero
• zero and two above

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.

Find the area of the shaded region. 

• 0.16
• 0.84
• 0.68
• 0.34

Find the area of the shaded region. 

• 0.16
• 0.84
• 0.68
• 0.34

Find the area of the shaded region. 

• 0.16
• 0.84
• 0.68
• 0.34

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

• 68%

• 95%

• 99.8%

• 50%

A line up for tickets to a local concert had an average (mean) waiting time of 20 minutes with a standard deviation of 4 minutes. If 2000 ticket buyers were in line, how many of them would expect to wait for less than 16 minutes?

• 320

• 1550

• 100

• 30

The mean temperature in Glens Falls for the month of February is 23 degrees with a standard deviation of 4.2 degrees.  Approximately what percent of days in February will have days below 23 degrees?

• 5%
• 34%
• 50%
• 68%

The average age of a group of fans at a hockey game is 36 years with a standard deviation of 8 years. What percent of fans are between 20 and 28 years old?

• 34%

• 16%

• 13.5%

• 2.5%