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1) A difference between calculating the sample mean and the population mean is

A) Only in the symbols, we use instead of μ and n instead of N

B) We divide the sum of the observations by n - 1 instead of n.

C) The observations are ranked and select the middle value for the population mean.

D) There are no differences.

2) Which of the following measures of central location is affected most by extreme values?

A) Median

B) Mean

C) Mode

D) Geometric mean

3) Which level of measurement is required for the median?

A) Nominal

B) Ordinal

C) Interval

D) Ratio

4) Which level of measurement is required for the mode?

A) Nominal

B) Ordinal

C) Interval

D) Ratio

5) In a set of observations, which measure of central tendency reports the value that occurs most often?

A) Mean

B) Median

C) Mode

D) Geometric mean

6) The weighted mean is a special case of the

A) Mean

B) Median

C) Mode

D) Geometric mean

7) The relationship between the geometric mean and the arithmetic mean is

A) They will always be the same.

B) The geometric mean will always be larger.

C) The geometric mean will be equal to or less than the mean.

D) The mean will always be larger than the geometric mean.

8) Suppose you compare the mean of raw data and the mean of the same raw data grouped into a frequency distribution. These two means will be

A) Exactly equal.

B) The same as the median.

C) The same as the geometric mean.

D) Approximately equal.

9) In a set of 10 observations the mean is 20 and the median is 15. There are 2 values that are 6, and all other values are different. What is the mode?

A) 15

B) 20

C) 6

D) None of the above.

10) Which of the measures of central tendency is the largest in a positively skewed distribution?

A) Mean

B) Median

C) Mode

D) Cannot tell from the information given.

11) Which of the following is not a measure of dispersion?

A) Range

B) Variance

C) Standard deviation

D) All of the above are measures of dispersion

12) A disadvantage of the range is

A) Only two values are used in its calculation.

B) It is in different units than the mean.

C) It does not exist for some data sets.

D) All of the above.

13) The mean deviation is

A) Based on squared deviations from the mean.

B) Also called the variance.

C) Based on absolute values.

D) Always reported in squared units.

14) The standard deviation is

A) Based on squared deviations from the mean.

B) In the same units as the mean.

C) Uses all the observations in its calculation.

D) All of the above.

15) The variance is

A) Found by dividing by N by the mean.

B) In the same units as the original data.

C) Found by squaring the standard deviation.

D) All of the above.

16) In a positively skewed distribution

A) The mean, median, and mode are all equal.

B) The mean is larger than the median.

C) The median is larger than the mean.

D) The standard deviation must be larger than the mean or the median.

17) Which of the following statements is true regarding the standard deviation?

A) It cannot assume a negative value.

B) If it is zero, then all the data values are the same.

C) It is in the same units as the mean.

D) All the above are all correct.

18) Under which of the following conditions would the standard deviation assume a negative value.

A) When all the data values were negative.

B) When more than half of the data values were negative.

C) If all the data values were the same.

D) The standard deviation cannot be negative.

19) For a stem-and-leaf display

A) Arrange the leaf values from smallest to largest.

B) Make sure the stem value is only one digit.

C) Do not allow stems with no leaf values.

D) All of the above.

20) Reference: Ref4-1

Questions 2 to 6 refer to the following information. It reports the number of TV sets sold per day at the Appliance Center.

1 11333

2 6

3 00234

4 555688999

5 1234

6 56788

7

8 8

This arrangement is called a

A) Frequency distribution

B) A frequency polygon

C) A pie chart

D) A stem-and-leaf chart

21) How many days were studied?

A) 11

B) 30

C) 50

D) None of the above

22) What was the smallest and largest number of sets sold per day?

A) 1, 8

B) 10, 80

C) 11,88

D) None of the above

23) How many days were there less than 30 sets sold?

A) 15

B) 6

C) 30

D) None of the above

24) The actual number of sets sold per day between 60 and 69 is

A) 65, 66, 67, 68, 68

B) 60, 69

C) Cannot tell from the information given

D) None of the above

25) The quartile deviation is

A) The square root of the variance.

B) Based on the middle 50 percent of the observations.

C) In squared units of the original data.

D) Appropriate only for symmetric distributions.

26) In a symmetric distribution

A) The mean, median, and mode are equal.

B) The mean is the largest measure of location.

C) The median is the largest measure of location.

D) The standard deviation is the largest value.

27) A coefficient of skewness of -2.73 was computed for a set of data. We conclude that

A) The mean is larger than the median.

B) The median is larger than the mean.

C) The standard deviation is a negative number.

D) Something is wrong because the coefficient of skewness cannot be less than -1.00.

28) A scatter diagram:

A) Is a graphic tool designed to portray the relationship between variables.

B) Uses interval or ratio scale data.

C) Does not allow negative values.

D) Both A and B are correct.

29) Which of the following is a correct statement about a probability?

A) It may range from 0 to 1.

B) It may assume negative values.

C) It may be greater than 1.

D) It cannot be reported to more than 1 decimal place.

30) An experiment is a

A) Collection of events.

B) Collection of outcomes.

C) Always greater than 1.

D) The act of taking a measurement or the observation of some activity.

E) None of the above is correct.

QNT-02

1) A difference between calculating the sample mean and the population mean is

A) Only in the symbols, we use instead of μ and n instead of N

B) We divide the sum of the observations by n - 1 instead of n.

C) The observations are ranked and select the middle value for the population mean.

D) There are no differences.

2) Which of the following measures of central location is affected most by extreme values?

A) Median

B) Mean

C) Mode

D) Geometric mean

3) Which level of measurement is required for the median?

A) Nominal

B) Ordinal

C) Interval

D) Ratio

4) Which level of measurement is required for the mode?

A) Nominal

B) Ordinal

C) Interval

D) Ratio

5) In a set of observations, which measure of central tendency reports the value that occurs most often?

A) Mean

B) Median

C) Mode

D) Geometric mean

6) The weighted mean is a special case of the

A) Mean

B) Median

C) Mode

D) Geometric mean

7) The relationship between the geometric mean and the arithmetic mean is

A) They will always be the same.

B) The geometric mean will always be larger.

C) The geometric mean will be equal to or less than the mean.

D) The mean will always be larger than the geometric mean.

8) Suppose you compare the mean of raw data and the mean of the same raw data grouped into a frequency distribution. These two means will be

A) Exactly equal.

B) The same as the median.

C) The same as the geometric mean.

D) Approximately equal.

9) In a set of 10 observations the mean is 20 and the median is 15. There are 2 values that are 6, and all other values are different. What is the mode?

A) 15

B) 20

C) 6

D) None of the above.

10) Which of the measures of central tendency is the largest in a positively skewed distribution?

A) Mean

B) Median

C) Mode

D) Cannot tell from the information given.

11) Which of the following is not a measure of dispersion?

A) Range

B) Variance

C) Standard deviation

D) All of the above are measures of dispersion

12) A disadvantage of the range is

A) Only two values are used in its calculation.

B) It is in different units than the mean.

C) It does not exist for some data sets.

D) All of the above.

13) The mean deviation is

A) Based on squared deviations from the mean.

B) Also called the variance.

C) Based on absolute values.

D) Always reported in squared units.

14) The standard deviation is

A) Based on squared deviations from the mean.

B) In the same units as the mean.

C) Uses all the observations in its calculation.

D) All of the above.

15) The variance is

A) Found by dividing by N by the mean.

B) In the same units as the original data.

C) Found by squaring the standard deviation.

D) All of the above.

16) In a positively skewed distribution

A) The mean, median, and mode are all equal.

B) The mean is larger than the median.

C) The median is larger than the mean.

D) The standard deviation must be larger than the mean or the median.

17) Which of the following statements is true regarding the standard deviation?

A) It cannot assume a negative value.

B) If it is zero, then all the data values are the same.

C) It is in the same units as the mean.

D) All the above are all correct.

18) Under which of the following conditions would the standard deviation assume a negative value.

A) When all the data values were negative.

B) When more than half of the data values were negative.

C) If all the data values were the same.

D) The standard deviation cannot be negative.

19) For a stem-and-leaf display

A) Arrange the leaf values from smallest to largest.

B) Make sure the stem value is only one digit.

C) Do not allow stems with no leaf values.

D) All of the above.

20) Reference: Ref4-1

Questions 2 to 6 refer to the following information. It reports the number of TV sets sold per day at the Appliance Center.

1 11333

2 6

3 00234

4 555688999

5 1234

6 56788

7

8 8

This arrangement is called a

A) Frequency distribution

B) A frequency polygon

C) A pie chart

D) A stem-and-leaf chart

21) How many days were studied?

A) 11

B) 30

C) 50

D) None of the above

22) What was the smallest and largest number of sets sold per day?

A) 1, 8

B) 10, 80

C) 11,88

D) None of the above

23) How many days were there less than 30 sets sold?

A) 15

B) 6

C) 30

D) None of the above

24) The actual number of sets sold per day between 60 and 69 is

A) 65, 66, 67, 68, 68

B) 60, 69

C) Cannot tell from the information given

D) None of the above

25) The quartile deviation is

A) The square root of the variance.

B) Based on the middle 50 percent of the observations.

C) In squared units of the original data.

D) Appropriate only for symmetric distributions.

26) In a symmetric distribution

A) The mean, median, and mode are equal.

B) The mean is the largest measure of location.

C) The median is the largest measure of location.

D) The standard deviation is the largest value.

27) A coefficient of skewness of -2.73 was computed for a set of data. We conclude that

A) The mean is larger than the median.

B) The median is larger than the mean.

C) The standard deviation is a negative number.

D) Something is wrong because the coefficient of skewness cannot be less than -1.00.

28) A scatter diagram:

A) Is a graphic tool designed to portray the relationship between variables.

B) Uses interval or ratio scale data.

C) Does not allow negative values.

D) Both A and B are correct.

29) Which of the following is a correct statement about a probability?

A) It may range from 0 to 1.

B) It may assume negative values.

C) It may be greater than 1.

D) It cannot be reported to more than 1 decimal place.

30) An experiment is a

A) Collection of events.

B) Collection of outcomes.

C) Always greater than 1.

D) The act of taking a measurement or the observation of some activity.

E) None of the above is correct.

QNT 561-3

1) A sample

a. Is a part of the population.

b. Has more than 30 observations.

c. Is usually identified as N.

d. All of the above.

2) Which of the following is not a reason for sampling?

a. The destructive nature of certain tests.

b. The physical impossibility of checking all the items in the population.

c. The adequacy of sample results.

d. All of the above are reasons for sampling.

3) Which of the following is not a method of probability sampling?

a. Random sampling

b. Systematic sampling

c. Stratified sampling

d. All of the above are methods of probability sampling.

4) In a simple random sample

a. Every kth item is selected to be in the sample.

b. Every item has a chance to be in the sample.

c. Every item has the same chance to be in the sample.

d. All of the above.

5) Suppose a population consisted of 20 items. How many different samples of n = 3 are possible?

a. 6840

b. 1140

c. 20

d. 120

6) The difference between the sample mean and the population mean is called the

a. Population mean.

b. Population standard deviation.

c. Standard error of the mean.

d. Sampling error.

7) The mean of the all the sample means and the population mean will

a. Always be equal.

b. Always be normally distributed.

c. Characterized by the standard error of the mean.

d. None of the above.

8) Suppose we have a population that follows the normal distribution. Which of the following statements is correct regarding the distribution of sample means?

a. The population standard deviation is always unknown.

b. The distribution of samples means will follow the uniform distribution.

c. The distribution of the sample means will also follow the normal distribution.

d. None of the above is correct.

9) Suppose we have a population that does not follow the normal distribution. If we select sample of what size will the distribution approximate the normal distribution?

a. 2

b. 5

c. 20

d. 30

10) The standard error of the mean is

a. The standard deviation of the sampling distribution of sample means.

b. Always normally distributed.

c. Sometimes less than 0.

d. None of the above.

11) A point estimate is

a. Always an estimate of the population mean.

b. Always equal to the population value.

c. An estimate of the population parameter.

d. None of the above

12) A confidence interval

a. Always includes the population parameter.

b. Decreases in width as the sample size is increased.

c. Cannot include a value of 0.

d. None of the above.

13) If we wished to decrease the width of a confidence interval, we would not do which of the following.

a. Increase the size of the sample.

b. Reduce the size of the population.

c. Decrease the level of confidence.

d. None of the above.

14) We wish to develop a confidence interval for the population mean. The shape of the population is not known, but we have a sample of 40 observations. We decide to use the 92 percent level of confidence. The appropriate value of z is:

a. 1.96

b. 1.65

c. 2.58

d. 1.75

15) Which of the following statements is not a characteristic of the t distribution?

a. It is a continuous distribution.

b. It has a mean of 0.

c. It is symmetrical.

d. Like z there is only one t distribution.

16) We wish to develop a confidence interval for the population mean. The population follows the normal distribution, the standard deviation of the population is 3, and we have a sample of 10 observations. We decide to use the 90 percent level of confidence. The appropriate value of to represent the level of confidence is

a. z =1.65

b. z = 1.96

c. t = 1.833

d. t = 1.812

17) The fraction or ratio of a sample possessing a certain trait is called a

a. Population.

b. Mean.

c. Confidence interval.

d. Proportion.

18) To develop a confidence interval for a proportion

a. We need to meet the binomial conditions

b. The sample should be at least 100.

c. B should be less than .05.

d. None of the above.

19) The finite population correction factor is used when

a. n is more than 30.

b. N is more than 1000.

c. nB is greater than 5.

d. n/N is more than .05.

20) We wish to estimate the population proportion. We want to be 95 percent confident of our results and we want the estimate to be with .01 of the population parameter. No estimate of the population proportion is available. What value should we use for p?

a. 1.96

b. .01

c. .50

d. We cannot complete the problem, we need more information.

21) The null hypothesis

a. Is a statement about the value of the population parameter.

b. Will always contain the equal sign.

c. Cannot include values less than 0.

d. Both a and b are correct.

22) The alternate hypothesis

a. Is accepted if the null hypothesis is rejected.

b. Will always contain the equal sign.

c. Tells the value of the sample mean.

d. None of the above.

23) The level of significance

a. Is frequently .05 or .01

b. Can be any value between 0 and 1.

c. Is the likelihood of rejecting the null hypothesis when it is true.

d. All of the above.

24) A Type I error is

a. The correct decision

b. A value determined from the test statistic

c. Rejecting the null hypothesis when it is true

d. Accepting the null hypothesis when it is false.

25) The critical value is

a. Calculated from sample information.

b. Cannot be negative.

c. The point that divides the acceptance region from the rejection region.

d. A value determined from the test statistic.

26) In a one-tailed test

a. The rejection region is in only one of the tails.

b. The rejection region is split between the tails.

c. The p-value is always less than the significance level.

d. The p-value is always more than the significance level.

27) To conduct a one sample test of means and use the z distribution as the test statistic

a. We need to know the population mean.

b. We need to know the population standard deviation.

c. We need nπ to be less than 5.

d. Both a and b are correct.

28) A p-value is

a. The same as the population proportion.

b. The same as the significance level.

c. The fraction of the population that has a particular characteristic.

d. The probability of finding a value of the test statistic this extreme when the null hypothesis is true.

29) A Type II error occurs when

a. We accept a false null hypothesis.

b. We reject a true alternate hypothesis.

c. We reject a false null hypothesis.

d. None of the above.

30) Which of the following statements are correct when deciding whether to use the z or the t distribution

a. Use zin a test of proportions when nπ and n(1 - π) are greater than or equal to 5.

b. Use z when we have a normal population and we know the standard deviation.

c. Use t when the population is normal and the population standard deviation is not known

d. All of the above statements are correct.

Solution Description

QNT 561 Se