91Ó°ÊÓ

A campus performance series features plays, music groups, dance troops, and stand-up comedy. The committee responsible for selecting the performance groups includes three students chosen at random from a pool of volunteers. This year, the 30 volunteers came from a variety of majors. However, the three students for the committee were all music majors. Does this fact indicate there was bias in the selection process and that the selection process was not random? Explain.

Categorize these measurements associated with student life according to level: nominal, ordinal, interval, or ratio. (a) Length of time to complete an exam (b) Time of first class (c) Major field of study (d) Course evaluation scale: poor, acceptable, good (e) Score on last exam (based on 100 possible points) (f) Age of student

Use a random-number table to generate a list of eight random numbers from 1 to 976. Explain your work.

Use a random-number table to simulate the outcomes of tossing a quarter 25 times. Assume that the quarter is balanced (i.e., fair).

A die is a cube with dots on each face. The faces have \(1,2,3,4,5,\) or 6 dots. The table below is a computer simulation (from the software package Minitab) of the results of rolling a fair die 20 times. $$\begin{array}{c|cccccccccc} {\text { DATA DISPLAY }} \\ \text { ROW } & \text { C1 } & \text { C2 } & \text { C3 } & \text { C4 } & \text { C5 } & \text { C6 } & \text { C7 } & \text { C8 } & \text { C9 } & \text { C10 } \\ \hline 1 & 5 & 2 & 2 & 2 & 5 & 3 & 2 & 3 & 1 & 4 \\ 2 & 3 & 2 & 4 & 5 & 4 & 5 & 3 & 5 & 3 & 4 \end{array}$$ (a) Assume that each number in the table corresponds to the number of dots on the upward face of the die. Is it appropriate that the same number appears more than once? Why? What is the outcome of the fourth roll? (b) If we simulate more rolls of the die, do you expect to get the same sequence of outcomes? Why or why not?

An important part of employee compensation is a benefits package, which might include health insurance, life insurance, child care, vacation days, retirement plan, parental leave, bonuses, etc. Suppose you want to conduct a survey of benefits packages available in private businesses in Hawaii. You want a sample size of \(100 .\) Some sampling techniques are described below. Categorize each technique as simple random sample, stratified sample, systematic sample, cluster sample, or convenience sample. (a) Assign each business in the Island Business Directory a number, and then use a random-number table to select the businesses to be included in the sample. (b) Use postal ZIP Codes to divide the state into regions. Pick a random sample of 10 ZIP Code areas and then include all the businesses in each selected ZIP Code area. (c) Send a team of five research assistants to Bishop Street in downtown Honolulu. Let each assistant select a block or building and interview an employee from each business found. Each researcher can have the rest of the day off after getting responses from 20 different businesses. (d) Use the Island Business Directory. Number all the businesses. Select a starting place at random, and then use every 50 th business listed until you have 100 businesses. (e) Group the businesses according to type: medical, shipping, retail, manufacturing, financial, construction, restaurant, hotel, tourism, other. Then select a random sample of 10 businesses from each business type.