IE 3200 Simple random sampling will ensure a representative

1. Simple random sampling will ensure a representative sample.

2. The whiskers on a box plot extend to the smallest and largest data pieces.

3. Variance can never be smaller than its standard deviation.

4. If a random variable, X, has the values , 3, 4, 5 or 6 andthen= 0.7.

5. Expected value of the probability distribution in problem 4 is 4.5.

6. For P(A) = 0.84, P(B) = 0.76, and P(A or B) = 0.90, the P(A and B) = 0.6384.

7. Given that P(A and B) = 0.45 and P(A) = 0.9 then P(B given A) = 0.05.

8. Significance level measures how frequently the conclusion will be correct over the long haul.

9. Confidence level is the proportion of times that an estimating procedure will be in error.

10. Standard deviation for a binomial distribution with n = 50 and p = 0.2 will be about 2.83.

11. A binomial distribution with n = 90 and p = 0.4 will have mean equal to 40.

12. Mutually exclusive and independent are synonymous statistical terms.

13. Multi-outcome experiments cannot be studied using the binomial distribution.

14. The probability that two carriers of cystic fibrosis will have an afflicted child in any given

birth is ¼. If two carriers plan to have 5 children, the probability that at least 1 of the 5 will be

afflicted with CF is approximately 0.6328.

15. Some sources claim that one out of two marriages fail. Assuming that figure is accurate,

given 20 randomly drawn newly married couples, the probability that exactly half of these

marriages will fail is approximately 0.1762.

II. COMPLETION

Use the given population data of employee weights to calculate the statistics that follow.

144 192 145 153 185 154 163 198 162 194 172

168 174 164 146 156 263 169 150 168 156 152

171 168 146 157 173

1. 1^st Quartile 2. Median 3. 3rd Quartile 4. Interquartile Range 5. 90^th percentile 6. Mean 7. Mode 8. Range 9. Variance 10. Standard Deviation 11. Coefficient of Variation 12. Weight to which upper whisker of a box plot would extend 13. Calculate the percentage given by 1 – 1/k^2 if k = 3.5 14. Form the interval (? +/- 3.5?) 15. What % of the weights fall into this interval?

III. MATCHING

1. Population a. P(A) = P(B)

2. Sample b. 1-1/k^2

3. Parameter c. Likelihood

4. Statistic d. Mean, Median, Mode

5. Quantitative e. P(Correct)

6. Qualitative f. Numerical

7. Confidence Level g. Population Measure

8. Significance Level h. P(A and B) = P(A) x P(B)

9. Descriptive Statistics i. Entire Group

10. Inferential Statistics j. All Possible Outcomes

11. Central Tendency k. Sample Measure

12. Variability l. Statistics Inferring Parameters

13. Probability m. Chart Of Class Intervals

14. Probability Range n. Categorical

15. Variable o. 0 = P(E) = 1

16. Frequency Distribution p. Part Of An Entire Group

17. Chebysheff’s Theorem q. P(Error)

18. Sample Space r. Population Characteristic

19. Equally Likely Events s. Range, Variance, Standard Deviation

20. Independent Events t. Extracting Information

IV. MULTIPLE CHOICE

1. Which of the following is not the goal of descriptive statistics?

Summarizing data

Displaying aspects of the collected data

Reporting numerical findings

Estimating characteristics of the population

None of these

2. Which of the following statements is not true?

One form of descriptive statistics uses graphical techniques

One form of descriptive statistics uses numerical techniques

In the language of statistics, population refers to a group of people

Statistical inference is used to draw conclusions or inferences about characteristics of populations based on sample data

None of these

3. The most appropriate type of chart for determining the number of observations at or below a

specific value is:

a histogram

a pie chart

a time-series chart

a cumulative frequency ogive

none of these

4. The total area of the six bars in a relative frequency histogram for which the width of each bar is

five units is:

6

5

11

1

none of these

5. Which of the following statements about pie charts is false?

Pie charts are graphical representations of the relative frequency distribution

Pie charts are usually used to display the relative sizes of categories for interval data.

Pie charts always have the shape of a circle

Area of each slice of a pie chart is the proportion of the corresponding category of the frequency distribution of a categorical variable

None of these

6. Which of the following statements is false?

All calculations are permitted on interval data

All calculations are permitted on nominal data

The most important aspect of ordinal data is the order of the data values

The only permissible calculations on ordinal data are ones involving a ranking process

None of these

7. Which of the following statements is false?

A frequency distribution counts the number of observations that fall into each of a series on intervals, called classes that cover the complete range of observations.

The intervals in a frequency distribution may overlap to ensure that each observation is assigned to an interval

Although the frequency distribution provides information about how the numbers in the data set are distributed, the information is more easily understood and imparted by drawing a histogram

The number of class intervals we select in a frequency distribution depends entirely on the number of observations in the data set.

None of these

8. The relative frequency of a class is computed by

dividing the frequency of the class by the number of classes

dividing the frequency of the class by the class width

dividing the frequency of the class by the total number of observations in a set

subtracting the lower limit of the class from the upper limit and multiplying difference by the number of classes

none of these

9. A modal class is the class that includes

the largest number of observations

the smallest number of observations

the largest observation in the data set

the smallest observation in the data set

none of these

10. The two graphical techniques usually used to present nominal data are

bar chart and histogram

pie chart and ogive

bar chart and pie chart

histogram and ogive

none of these

11. The most important and common graphical presentation of interval data is a

bar chart

histogram

pie chart

cumulative frequency distribution

none of these

12. The relationship between two interval variables is graphically displayed by a

scatter diagram

histogram

bar chart

pie chart

none of these

13. The effect of making the slope of a line graph appear steeper can be created by:

Stretching the vertical axis.

Shrinking the horizontal axis.

Stretching the horizontal axis.

Both a and b

None of these

14. Possible methods of creating distorted impressions with bar charts include:

Stretching the vertical axis.

Shrinking the horizontal axis

Constructing the bars so that their widths are proportional to their heights.

All of the above

None of these

15. Which of the following statements about the arithmetic mean is not always correct?

The sum of the deviations from the mean is zero

Half of the observations are on either side of the mean

The mean is a measure of the middle (center) of a distribution

The value of the mean times the number of observations equals the sum of all of the observations.

None of these

16. In a histogram, the proportion of the total area, which must be to the left of the median, is:

exactly 0.50

less than 0.50 if the distribution is skewed to the left

more than 0.50 if the distribution is skewed to the right

between 0.25 and 0.60 if the distribution is symmetric and unimodal

none of these

17. If two data sets have the same range:

the distances from the smallest to largest observations in both sets will be the same

the smallest and largest observations are the same in both sets

both sets will have the same mean

both sets will have the same interquartile range

none of these

18. A population of 20 exams has a standard deviation of 3. The sum of the squared deviations

from the mean is:

9

60

171

180

none of these

19. Which measure of central location is meaningful when the data are nominal?

The arithmetic mean

The geometric mean

The median

The mode

None of these

20. Chebyshev’s Theorem states that the percentage of measurements in a data set that fall within

4 standard deviations of their mean is:

93.75%

at least 93.75%

91.8%

at least 91.8%

none of these

21. The Empirical Rule states that the percentage of measurements in a data set

(provided that the data set has a bell-shaped distribution) that falls within three standard

deviations of their mean is:

68%

75%

95%

99%

none of these

22. Since the population is always larger than the sample, the population mean:

is always larger than the sample mean

is always smaller than the sample mean

is always larger than or equal to the sample mean

is always smaller than or equal to the sample mean

none of these

23. Which of the following summary measures is affected least by outliers?

The median

The variance

The range

The mean

None of these

24. Which of the following summary measures cannot be easily approximated from a box-and-

whisker plot?

The range

The interquartile range

The second quartile

The standard deviation

None of these

25. The average score for a class of 30 students was 75. The 20 male students in the class

averaged 70. The 10 female students in the class averaged:

70

75

80

85

none of these

26. Which of the following is not a measure of variability?

The range

The variance

The interquartile range

The standard deviation

None of these

27. The length of the box in the box-and-whisker plot portrays the:

median

range

interquartile range

first and third quartiles

none of these

28. Which of the following statements is true for the following data values: 7, 5, 6, 3, 7, 8, and 12?

The mean, median and mode are all equal

Only the mode and median are equal

Only the mean and mode are equal

Only the median and mean are equal

None of these

29. When every possible sample with the same number of observations is not equally likely to be

chosen, the selected sample is called:

Biased

Stratified

Cluster

Random

None of these

30. Which of the following statements is correct in questionnaire design?

The questionnaire and questions should be kept as short as possible.

A mixture of dichotomous, multiple-choice, and open-ended questions may be used.

Leading questions must be avoided.

All of the above are correct statements

None of these