Statistics and Probability Quiz

Which of the following refers to a numerical quantity that is assigned to the outcome of an experiment?

• probability

• probability distribution

• random variable

• variable

What is the sum of the probabilities of a random variable?

• 0

• 1

• ½

• 2

How many standard deviations are there in each inflection point?

• 0

• 1

• 2

• 3

What value of a data set represents the center of the curve?

• µ

• α

• σ

• ∑

What percent of a normal distribution lies outside of ±3 standard deviations?

• 0.3%

• 0.15%

• 99.7%

• 100%

What percentage of data falls within one standard deviation of the mean?

• 25%

• 50%

• 68%

• 95%

Which of the following determines the width of the curve?

• mean

• standard curve

• standard deviation

• variation

What is the area under the normal curve between z = - 2 and z = 2?

• 0.6286

• 0.6826

• 0.9544

• 0.9554

Which value is found at the center of the normal curve?

• mean

• median

• mode

• all of the above

Given a test that is normally distributed with a mean of 90 and standard deviation of 10. What score is one standard deviation above the mean?

• 80

• 90

• 100

• 110