Suppose the number of babies born each hour at a hospital follows a Poisson distribution with a mean of 3. Some people believe that the presence of a full moon increases the number of births that take place.
Suppose during the presence of a full moon, the hospital experienced eight consecutive hours with more than four births each hour. Based on this fact, comment on the belief that the full moon increases the number of births.
A) The belief is supported as the probability of observing this many births would be 0.00000137.
B) The belief is not supported as the probability of observing this many births is 0.185.
C) The belief is not supported as the probability of observing this many births is 0.00000137.
D) The belief is supported as the probability of observing this many births would be 0.185.
Q. 2In a completely randomized design experiment, 10 experimental units were randomly chosen for each of three treatment groups and a quantity was measured for each unit within each group.
In the first steps of testing whether the means of the three groups are the same, the sum of squares for treatments was calculated to be 3,110 and the sum of squares for error was calculated to be 27,000.
Complete the ANOVA table.
Source df SS MS F
Treatments
Error
Total
Q. 3If a data set is normally distributed, what is the proportion of measurements you would expect to fall within
A) 100 B) 95 C) 68 D) 50
Q. 4Name and describe the kind of bias that might be present if the statistics teacher decides that instead of randomly selecting students to survey on how they feel about the course she just
a. asks students to volunteer for the survey.
b. gives the survey during class one day.
Management at a large retail chain is concerned about the possibility of drug abuse by people who work there. They decide to check on the extent of the problem by having a random sample of the employees undergo a drug test. Several plans for choosing the sample are proposed.
a. Randomly select ten stores around the country and survey all the employees that work at those stores.
b. Choose the fourth person that arrives to work for each shift.
c. There are four employee classifications: supervisors, fulltime clerks, part-time clerks, and maintenance staff. Randomly select ten people from each category.
d. Each employee has a three-digit identification number. Randomly choose 40 numbers.
Q. 5Suppose the number of babies born each hour at a hospital follows a Poisson distribution with a mean of 7. Find the probability that exactly six babies will be born during a particular 1-hour period at this hospital.
A) 0.000005 B) 0.000260 C) 0.149003 D) 0.018625
Q. 6If the teacher in simply surveyed all of her students, what kind of sampling would that be? Explain why this method is biased. Be sure to name the kind(s) of bias you describe and link it to the variable of interest.
What will be an ideal response?
Q. 7What type of car is more popular among college students, American or foreign? One hundred fifty-nine college students were randomly sampled and each was asked which type of car he or she prefers.
A computer package was used to generate the printout below for the proportion of college students who prefer American automobiles.
SAMPLE PROPORTION = .390998
SAMPLE SIZE = 159
UPPER LIMIT = .464240
LOWER LIMIT = .331153
What proportion of the sampled students prefer foreign automobiles?
A) .464240 B) .390998 C) .331153 D) .609002
Q. 8Complete the ANOVA table.
Source df SS MS F
Treatments 3 857.1
Error 8 372.8
Total
What will be an ideal response?