Sample Hypothesis Test Questions (No computation required)
Dr. Theodora Rivia is interested in finding something that her BH students are better at
doing than the students at SDSM&T. One day, as she gazed at her students driving past
campus with their heads hanging out the window and tongues flapping in the wind, she
had an insight. The next day, she decided to measure how many licks it takes to get to
the Tootsie Roll center of a Tootsie Pop.
1. If T. Rivia finds that 15 SDSM&T students take an average of 26 licks to get to the
center of an Orange Tootsie Pop, with a standard deviation of 1.80 licks; and if she finds
that the average licks to center for 12 BH students eating Orange Tootsie Pops is 13 (with
a standard deviation of 1.81 licks):
a.) What are the appropriate Null and Alternative Hypotheses to find out if there is a
difference in required licks between the two groups of students?
b.) What is the most appropriate test statistic to compute in order to find this difference?
2. T. Rivia thinks that maybe the BH students can lick quicker because they have bigger
tongues. She creates a scatter-plot, and finds some negative correlation between tongue
size and the number of licks to the center of the Tootsie Pop. When she measures the
tongue size of 2000 of the BH students, she finds a mean of 6 inches and a standard
deviation of 0.700 inches. When she tries to measure the SDSM&T students, she is
severely bitten after measuring 7 students, and quits with the following data: mean = 4.7
inches, standard deviation of 0.698 inches.
a.) What are the appropriate Null and Alternative Hypotheses to find out if the BH
students have bigger tongues than the SDSM&T students?
b.) What is the most appropriate test statistic to compute in order to find if the tongues
are bigger?
c.) What are the appropriate Null and Alternative Hypotheses to find out if the BH
students have less variation in tongue sizes than the SDSM&T students?
b.) What is the most appropriate test statistic to compute in order to find out if there is
less variation?
3. Her colleague, Professor Igor Vel, notices that BH students seem to drool more than
SDSM&T students, especially when licking Red Tootsie Pops. Dr. I. Vel takes 12 BH
students, and has each of them lick to the center of a red pop, and he has 12 SDSM&T
students lick to the center as well. He finds that for SDSM&T students, the mean is 24
licks, with a variance of 5.2 licks2; and for the BH students, the average is 18 licks, with a
variance of 3.1 licks2.
a.) What are the appropriate Null and Alternative Hypotheses to find out if the SDSM&T
student’s drool dissolves less Tootsie Pop than the BH students?
b.) What is the most appropriate test statistic to compute in order to find out if there is a
less drool solvent in an SDSM&T student?
c.) What are the appropriate Null and Alternative Hypotheses to find out if the BH
students have less variation in drool than the SDSM&T students?
b.) What is the most appropriate test statistic to compute in order to find out if there is
less variation in BH student drool?