***** PLEASE MAKE SURE THAT ALL WORK IS AUTHENTIC***** ****** THIS ASSIGNMENT HAS 2 PARTS / PLEASE LABEL EACH PART SEPARATELY WITH REFERENCES WHEN COMPLETED****** PART 1: Assignment 1: What is S
ORG 205 – Statistical Procedures
Week 1 – Problem Set
Directions: Answer the questions below. When applicable, please show all your work.
Section 1.1
(1 point) Auto Mileage: What are the average miles per gallon (mpg) for all new cars? Using Consumer Reports, a random sample of 35 new cars gave an average of 21.1 mpg.
(a) Identify the variable.
(b) Is the variable quantitative or qualitative?
(c) What is the implied population?
(3 points) Levels of Measurement: Categorize these measurements associated with a robotics company according to level: nominal, ordinal, interval, or ratio.
(a) Salesperson’s performance: below average, average, above average
(b) Price of company’s stock
(c) Names of new products
(d) Temperature (F) in CEO’s private office
(e) Gross income for each of the past 5 years
(f) Color of product packaging
Section 1.2
(1.5 points) Critical Thinking: Consider the students in your statistics class as the population and suppose they are seated in four rows of 10 students each. To select a sample, you toss a coin. If it comes up heads, you use the 20 students sitting in the first two rows as your sample. If it comes up tails, you use the 20 students sitting in the last two rows as your sample.
(a) Does every student have an equal chance of being selected for the sample? Explain.
(b) Is it possible to include students sitting in row 3 with students sitting in row 2 in your sample? Is your sample a simple random sample? Explain.
(c) Describe a process you could use to get a simple random sample of size 20 from a class of size 40.
(2.5 Points) Benefits Package: An important part of employee compensation is a benefits package, which might include health insurance, life insurance, childcare, 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 50th 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
Section 1.3
(4 points) Gathering Data: Which technique for gathering data (sampling, experiment, simulation, or census) do you think was used in the following studies?
(a) An analysis of a sample of 31,000 patients from New York hospitals suggests that the poor and the elderly sue for malpractice at one-fifth the rate of wealthier patients (Journal of the American Medical Association).
(b) The effects of wind shear on airplanes during both landing and takeoff were studied by using complex computer programs that mimic actual flight.
(c) A study of all league football scores attained through touchdowns and field goals was conducted by the National Football League to determine whether field goals account for more scoring events than touchdowns (USA Today).
(d) An Australian study included 588 men and women who already had some precancerous skin lesions. Half got a skin cream containing a sunscreen with a sun protection factor of 17; half got an inactive cream. After 7 months, those using the sunscreen with the sun protection had fewer new precancerous skin lesions (New England Journal of Medicine).
(3 points) Manipulation: The New York Times did a special report on polling that was carried in papers across the nation. The article pointed out how readily the results of a survey can be manipulated. Some features that can influence the results of a poll include the following: the number of possible responses, the phrasing of the question, the sampling techniques used (voluntary response or sample designed to be representative), the fact that words may mean different things to different people, the questions that precede the question of interest, and finally, the fact that respondents can offer opinions on issues they know nothing about.
(a) Consider the expression “over the last few years.” Do you think that this expression means the same time span to everyone? What would be a more precise phrase?
(b) Consider this question: “Do you think fines for running stop signs should be doubled?” Do you think the response would be different if the question “Have you ever run a stop sign?” preceded the question about fines?
(c) Consider this question: “Do you watch too much television?” What do you think the responses would be if the only responses possible were yes or no? What do you think the responses would be if the possible responses were rarely, sometimes, or frequently?
