Prob & Stats Semester Exam

Joe scores 70% on a 50-point test and 90% on a 100-point test. What is the weighted mean?

• 80%

• 83%

• 85%

• 87%

Mr. A records the # of students in class daily. What type of graph should he use to show how attendance varies during the year?

• Pie graph

• Pictograph

• Time series graph

• Pareto chart

A coin has 2 sides. If we say the chance of getting a head is ½, that’s an example of what type of probability?

• empirical

• subjective

• classical

• all of these

What is the midpoint of the class 9.5 – 14.5?

• 12

• 12.5

• 12.25

• 13

A commercial states a car is 15% more fuel efficient. This is an example of what?

• Changing the subject

• detached statistics

• ambiguous averages

• Suspect samples

What do we call a characteristic of a subject that can assume different values?

• datum

• sample

• variable

• exponent

If the mean of a data set is 10 and its variance is 4, what is its coefficient of variation?

• 0.2

• 0.4

• 2.5

• 5

What is the classical probability that a coin, tossed 4 times, will come up “heads” on all 4 tosses?

• 1/2

• 1/4

• 1/8

• 1/16

A continuous variable can have …

• no values

• a finite whole number of values

• infinitely many values

• two values

Mathematical probabilities can have values of …

• between -1 and +1

• between 0 and 1 inclusive

• any positive real number

• any integer