The sum of the probabilities of a discrete probability distribution must be
A) greater than one. B) less than or equal to zero.
C) equal to one. D) between zero and one.
Q. 2Before premiering a blockbuster movie at a theater, test screenings are done beforehand. A small number of selected theaters are chosen geographically throughout the country.
Each theater chosen is supposed to be representative of theatergoers in that area. Everyone is interviewed when the movie is over. Identify the type of sampling used in this example.
A) Stratified sampling B) Systematic sampling
C) Cluster sampling D) Attempted census
Q. 3A company which designs sports shoes has made an improvement to their popular running shoe. They hope that athletes wearing the new running shoe will be able to run faster over short distances.
They will use a paired sample to determine whether the mean time to run 100 meters for sprinters wearing the new running shoe is less than the mean time to run the 100 meters for sprinters wearing the old running shoe. Identify the variable for the proposed hypothesis test.
A) Type of sports shoe worn B) Type of athlete
C) Distance run D) Time to run 100 meters
Q. 4Given the table of probabilities for the random variable x, does this form a probability distribution? Answer Yes or No.
x 5 10 15 20
P(x) 0.10 -0.30 0.50 0.70
A) Yes B) No
Q. 5A pollster uses a computer to generate 500 random numbers and then interviews the voters corresponding to those numbers. Identify the type of sampling used in this example.
A) Simple random sampling B) Cluster sampling
C) Systematic random sampling D) Stratified sampling
Q. 6A pharmaceutical company wants to determine whether its new antianxiety medication has any effect on resting pulse rate.
They will use a paired sample to determine whether the mean resting pulse rate for adults not taking the antianxiety medication differs from the mean resting pulse rate for adults who are taking the antianxiety medication. Identify the variable for the proposed hypothesis test.
A) Amount of medication taken
B) Resting pulse rate
C) Anxiety level
D) Difference between mean resting pulse rate for those not on the medication and the mean resting pulse rate for those on the medication
Q. 7A random variable is
A) a numerical measure of the outcome of a probability experiment.
B) a qualitative attribute of a population.
C) the variable for which an algebraic equation is solved.
D) generated by a random number table.
Q. 8The number of violent crimes committed in a day possesses a distribution with a mean of 1.7 crimes per day and a standard deviation of four crimes per day.
A random sample of 60 days was observed, and the sample mean number of crimes for the sample was calculated. The data that was collected in this experiment could be measured with a __________ random variable.
A) discrete B) continuous