More Stats Midterm Practice

23. The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample at least 6 are female? a. 0.3154 b. 0.6846 c. 0.0168 d. 0.8936

a. 0.3154

8. A histogram is a. a graphical presentation of a frequency or relative frequency distribution. b. a graphical method of presenting a cumulative frequency or a cumulative relative frequency distribution. c. the history of data elements. d. the same as a pie chart.

a. a graphical presentation of a frequency or relative frequency distribution.

7. Data that provide labels or names for categories of like items are known as _____ data. a. categorical b. quantitative c. labeled d. Qualitative

a. categorical

28. The mean of a standard normal probability distribution a. is always equal to zero. b. can be any value as long as it is positive. c. can be any value. d. is always greater than zero.

a. is always equal to zero.

2. A restaurant asks their customers to fill out a questionnaire indicating whether their service was excellent, very good, good, or poor. The rating scale used is an example of the _____ scale. a. ordinal b. ratio c. nominal d. interval

a. ordinal

4. Height is an example of a variable that uses the _____ scale. a. ratio b. interval c. nominal d. ordinal

a. ratio

30. For a standard normal distribution, the probability of obtaining a z value between -1.4 to -0.35 is a. 0.7176. b. 0.2824. c. 0.5561. d. 0.4439.

b. 0.2824.

10. Which of the following provides a measure of central tendency for the data? a. Standard deviation b. Mean c. Variance d. Range

b. Mean

12. Which of the following is not a measure of variability? a. The range b. The midrange c. The standard deviation d. The interquartile range

b. The midrange

18. Each individual outcome of an experiment is called a. the sample space. b. a sample point. c. a trial. d. an event.

b. a sample point.

27. The center of a normal curve a. is always equal to zero. b. is the mean of the distribution. c. cannot be negative. d. is the standard deviation.

b. is the mean of the distribution.

15. A group of students had dinner at a local restaurant. The total bill for the dinner was $364.99. Each student paid his/her equal share of the bill, which was $21.47. How many student's were at the dinner? a. 124 b. 365 c. 17 d. 22

c. 17

21. Twenty percent of the students in a class of 400 are planning to go to graduate school. The standard deviation of this binomial distribution is a. 20. b. 64. c. 8. d. 40.

c. 8.

25. Consider the probability distribution below. x f(x) 10 .2 20 .4 30 .3 40 .1 The variance of x equals a. 9. b. 23. c. 81. d. 610.

c. 81.

1. The process of capturing, storing, and maintaining data is known as a. data manipulation. b. data mining. c. data warehousing. d. big data.

c. data warehousing.

17. The most frequently occurring value of a data set is called the a. mean. b. median. c. mode. d. outlier.

c. mode.

6. The percent frequency of a class is computed by a. multiplying the frequency by 100. b. dividing the relative frequency by 100. c. multiplying the relative frequency by 100. d. dividing the frequency by 100.

c. multiplying the relative frequency by 100.

11. The difference between the largest and the smallest data values is the a. variance. b. interquartile range. c. range. d. coefficient of variation.

c. range.

5. Data are a. always numeric. b. always non-numeric. c. the raw material of statistics. d. always categorical.

c. the raw material of statistics.

24. The student body of a large university consists of 65% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample at least 6 are male? a. 0.0036 b. 0.1691 c. 0.4278 d. 0.0253

d. 0.0253

x is a normally distributed random variable with a mean of 7 and a standard deviation of 2. The probability that x is between 6.48 and 7.56 is a. 0.9524. b. 0.0476. c. 0.7872. d. 0.2128.

d. 0.2128.

9. The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 - 9 20 10 - 19 80 20 - 29 200 30 - 39 100 The midpoint of the third class is a. 25.5 b. 24 c. 25 d. 24.5

d. 24.5

16. The closing stock price of MNM Corporation for the last 7 trading days is shown below. Day Stock Price 1 24 2 27 3 24 4 28 5 25 6 30 7 31 The variance is a. 2.828. b. 2.618. c. 8. d. 6.857.

d. 6.857.

13. The sum of deviations of the individual data elements from their mean is a. always greater than zero. b. always less than zero. c. sometimes greater than and sometimes less than zero, depending on the data elements. d. always equal to zero.

d. always equal to zero.

26. The standard deviation of a normal distribution a. is always 0. b. is always 1. c. can be any value. d. cannot be negative.

d. cannot be negative.

3. The measure of location which is the most likely to be influenced by extreme values in the data set is the a. range. b. median. c. mode. d. mean.

d. mean.

14. Which of the following symbols represents the size of the sample? a. σ2 b. σ c. N d. n

d. n

22. The variance Var(x) for the binomial distribution is given by equation a. np(n - 1). b. np(1 - np). c. n(1 - p). d. np(1 - p).

d. np(1 - p).

20. A numerical description of the outcome of an experiment is called a a. descriptive statistic. b. probability function. c. variance. d. random variable.

d. random variable.

19. If two events are independent, then a. they must be mutually exclusive. b. the sum of their probabilities must be equal to one. c. their intersection must be zero. d. the product of their probabilities gives their intersection.

d. the product of their probabilities gives their intersection.