# statistics concept

1) Determine whether the evaluated group is a population or a sample.

a) Based on a randomly selected group of 500 patients with high cholesterol, it was found that 67% have heart disease. Is this a population or a sample? Explain your answer.

b) An investigation of 150 randomly selected local restaurants concluded that 42% of local restaurants have serious health code violations. Is this a population or a sample; explain your answer.

2) Determine whether the given value is a statistic or a parameter.

a) A researcher determines that 42.7% of all downtown office buildings have ventilation problems. Is this a statistic or a parameter? Explain your answer.

b) After taking the first exam, 15 of the students dropped the class. Is this a statistic or a parameter? Explain your answer.

3) Identify the type of sampling used.

a) A tax auditor selects every 1000th income tax return that is received. What type of sample is this and why?

b) The name of each contestant is written on a separate card, and the cards are placed in a bag with three names being picked from the bag. What type of sample is this and why?

4) Is the study experimental or observation and why?

a) A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

5) Select the study that is most appropriate and EXPLAIN WHY it is most appropriate for the study.

a) Is the aspirin produced by a particular pharmaceutical company better than that of a competitor at relieving headaches? Which of the following would best be used to study this: 1) a case-controlled observation; 2) an observation; 3) a double-blind experimental procedure; and 4) and experimental procedure.

Chapter Two

1) Identify the following variables as either qualitative or quantitative and EXPLAIN your answers.

a. The number of people on a jury.

b. The color of your house.

2) Identify the number as either continuous or discrete and EXPLAIN your answers.

a. The average height of all freshmen entering college in a certain year is 68.4 inches.

b. The number of limbs on a 2-year-old oak tree is 21.

3) Determine which of the four levels of measurement is most appropriate and explain your answer.

a. Temperatures in degrees Fahrenheit of the ocean at various depths.

b. The rank of individuals in the military.

c. The number of people with blue, brown and red hair in a classroom.

4) Determine the following (show your work):

a. The speed of a new microprocessor is 800MHZ, but a new test of its speed gives a measurement of 820MHZ. What is the absolute error? What is the relative error?

b. Convert 1/16 to a percent

c. Convert 0.45 to a percent

d. Humanities majors spend an average of $115 per course on books. Mathematics majors spend an average of $70 per course on books.

What is the percent difference between the two amounts relative to the amount for mathematics majors (round to the nearest percent)?

e. Suppose that the cost of a statistics text was $50 in 1985 and is $100 in 2000. What is the "Statistics Text Index" number, rounded to the nearest tenth, for the 2000 edition with the 1985 price as the reference value?

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#### Solution Summary

The solution provides explanations for many statistics concept problems.

Multiple Choice Questions on Statistics concepts - sample, population, mean, median, mode, range, standard deviation, variance, probability, confidence interval estimate

Use the following information to answer questions 1 - 3. Breakdown how you got the answer.

George Johnson, a concerned citizen, has decided to conduct a study of the voters in his town to determine if they approve of the way the mayor is running the government. He intends to ask 30 citizens of voting age their views in order to obtain an approval rating (a percentage) that will be published in the local newspaper. George comes from a large town. The town clerk, who monitors the voting booths, informed him that all the voters in the entire town registered at a recent election, and 310,000 votes were counted.

1. The voters in the town represent the

1. sample.

2. variable of interest.

3. population of interest.

a. 1

b. 2

c. 3

d. 2 and 3

2. The mayor's approval rating is the

1. sample.

2. variable of interest.

3. population of interest.

a. 1.

b. 2.

c. 3.

d. 2 and 3.

4. If the size of a population is N and the size of a sample of the same population is n, then the correct relationship between N and n is

a. N < n.

b. n > N.

c. N >= n.

d. n = N - 1.

Use the following for questions 5-10

At the start of the 1999 NCAA men's basketball tournament, 64 teams were invited to compete for the national championship. Below is the number of victories that a sample of 8 of these teams had obtained during the regular season:

32 12 28 22 20 25 22 19

5. What is the sample mean number of regular season victories?

6. What is the sample median number of regular season victories?

7. What is the sample mode number of regular season victories?

8. What is the sample range in values of the number of regular season victories?

9. What is the sample variance of regular season victories?

10. What is the sample standard deviation of regular season victories?

11. What information does comparing the mean and median provide?

12. Margaret Morris just correctly computed a standard deviation of 6.0 from a sample of 50 observations. What is the variance of Margaret's sample?

a. 0.12

b. 0.72

c. 36

d. 44

13. Kim Fernando has just found the variance of a sample of 32 observations to be 64.0 by using a formula that is programmed into her new calculator. Therefore, what is the sample standard deviation?

a. 2.0

b. 4.0

c. 8.0

d. 4,096

14. A store manager found that 20 of his 50 ties in stock are striped. What is the probability that a random selection of a tie to show a customer will be striped?

a. 0

b. 0.2

c. 0.4

d. 0.5

15. The minimum value that any probability can be is _________ and the maximum value is _________.

a. 0, 1

b. -1, 0

c. -1, 0

d. 0, infinity

16. If the probability that Jeff Springs will win the high jump at the state meet is 0.2, the probability that someone other than Jeff wins the high jump is

a. 0

b. 0.2

c. 0.5

d. 0.8

17-20. A university wants to estimate the average amount of money that students spend on textbooks in a semester. It takes a random sample of 45 students and finds that an average amount of money spent was $282 with a standard deviation of $21. Find a 95% confidence interval estimate for the true mean amount of money spent on textbooks in a semester.

Please see the attachment.

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