1.On a standard measure of hearing ability, the mean is 300, and the standard deviation is 20. Provide the Z scores for persons whose raw scores are 340, 310, and 260. Provide the raw scores for persons whose Z scores on this test are 2.4, 1.5, and -4.5.
2.Using the unit normal table, find the proportion under the standard normal curve that lies in the tail for each of the following:
a.z = 1.00 has a proportion of 0.1587
b.z = -1.05 has a proportion of 0.1469
c.z = 0 has a proportion of 0.5
d.z = 2.80 has a proportion of 0.0026
e.z = 1.96 has a proportion of 0.0250
3.Suppose the scores of architects on a particular creativity test are normally distributed. Using a normal curve table (pp. 477–480 of the text), what percentage of architects have Z scores
a.above .10? goes to .4602 or 46.02%
b.below .10? at 0.5398 or 53.98%
c.above .20? at 0.4207 or 42.07%
d.below .20? at 0.5793 or 57.93%
e.above 1.10? at 0.1357 or 13.57%
f.below 1.10? at 0.8643 or 86.43%
g.above -.10? at 0.5398 or 53.98%
h.below -.10? at .4602 or 46.02%
4.A statistics instructor wants to measure the effectiveness of his teaching skills in a class of 102 students (N = 102). He selects students by waiting at the door to the classroom prior to his lecture and pulling aside every third student to give him or her a questionnaire.
a.a. Is this sample design an example of random sampling? Explain.
b.Assuming that all students attend his class that day, how many students will the instructor select to complete his questionnaire?
5.Suppose you were going to conduct a survey of visitors to your campus. You want the survey to be as representative as possible.a.How would you select the people to survey?
Making some assumptions (that there is a register for visitor for example): I would use the list of upcoming visitors throughout the year, I would then assign a number to each individual on this list and use an automatic randomizer to select those who would receive a questionnaire.
b.Why would that be your best method?