Statistical Review

A principal wants to know how teachers feel about changes to their schedule. He decides to ask a sample of 20 teachers. Classify each sampling method.

Survey the first 20 teachers who volunteer.

• Simple Random

• Self-Select

• Cluster

• Stratefied

Which is the closest to what most people would call the "average?"

• mean
• median
• mode
• range

In the last 5 games, LeBron James scored 22, 22, 18, 12, and 21 points. What is LeBron's Mean (Average) score per game in the past 5 games?

•  19 points per game
• 95 points per game
• 18.6 points per game
• 22 points per game

The scatter plot below shows the number of books read by students in Mrs. Hall’s English class and their final grades. Which statement represents the best description about the line of best fit?

• The more books students read, the lower their English grade.

• The more books students read, the higher their English grade.

• The fewer books students read, the higher their English grade.

• No relationship exists between the number of books students read and their English grades.

A restaurant sells pizza for the prices in the data table.  Calculate the linear regression equation of the data.

• y = 1.5x + 12
• y = 12x + 1.5
• y = 0.67x - 8
• y = -8x + 0.67

What type of correlation does this graph show?

• A) Positive

• B) negative

• C) none

• D) all of the above

Find the area of the shaded region.

• 16%

• 84%

• 68%

• 34%

In a factory, the weight of the concrete poured into a mold by a machine follows a normal distribution with a mean of 1150 pounds and a standard deviation of 22 pounds. Approximately 95% of molds filled by this machine will hold weights in what interval? 

• 1084 to 1216 pounds 
• 1106 to 1150 pounds 
• 1106 to 1194 pounds 
• 1128 to 1172 pounds

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What percentage of students at the high school have a GPA between 2.3 and 3.5?

• 68%
• 99.7%
• 95%
• 84%

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

• 68%
• 34%
• 16%
• 2.5%