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- Mean, mode, and median are measures of central tendency of ungrouped data. A. True B. False 2. The median is the most frequently occurring value in a set of data. A. True B. False 3. An advantage of median as the measure of central tendency is that it uses all of the information from the numbers in the data set. A. True B. False 4. A advantage of the median instead of using mean as the measure of central tendency is that it is not affected by extremely large or extremely small values in the data set. A. True B. False 5. The median and the second quartile of a data set are always equal. A. True B. False 6. Depending on the numbers in a data set the sum of deviations from the arithmetic mean for the set of numerical data may be greater than or less than zero. A. True B. False 7. The variance is the average of the squared deviations about the arithmetic mean for a set of numbers. A. True B. False
- Standard deviation is the square root of the variance. A. True B. False
- The mode for grouped data is the class midpoint of the modal class. A. True B. False
- What is the median for the following five numbers? 240, 164, 116, 218, 219
A. 223 B. 256 C. 216 D. 218 E. 229
- What is the mean for the following five numbers? 240, 164, 116, 218, 219
A. 123. B. 156. C. 130. D. 191. E. 130.
- The central tendency or center of a set of data may be described by its . A. variance B. standard deviation C. mean D. spread
- The mode of a set of numerical data is the.
A. largest number in the data set B. smallest number in the data set C. most frequently occurring number in the data set
D. 7.
- A city police officer using radar checked the speed of 26 cars as they were travelling down a city street and the data is given as below: 27 23 22 38 43 24 25 23 22 54 31 30 29 48 27 25 29 28 26 33 25 21 23 34 20 23 What are the mean, median and mode for this dataset: A. 28, 27, 24 B. 29. 26.5, 24 C. 28, 27, 23 D. 29, 26.5, 23
- The median of a set of numerical data is the.
A. largest number in the data set B. smallest number in the data set C. most frequently occurring number in the data set D. middle value in the ordered set of data
- What is the percentage of the dataset below the second quartile of a data set?
A. 25% B. 50% C. 75% D. 95%
- Mean absolute deviation, standard deviation, and variance are all measures of the . A. central tendency of a data set B. variability of a data set C. association within a data set D. shape of a data distribution
- The sum of deviations from the mean for a data set.
A. measures the variability of the data set B. is greater than zero
C. is less than zero D. is equal to zero
- If we know the variance, we can find the standard deviation by.
A. dividing the observation number minus 1 from the variance B. subtracting the mean from the variance C. squaring the variance D. taking the square root of the variance
- What is the range of dataset 22, 5, -7, 11, 2, 11?
A. 7. B. 29. C. 11. D. 7.
- Mean absolute deviation of a set of numerical data is always.
A. zero B. non-positive C. non-negative D. equal to the standard deviation
- What is the mean absolute deviation of dataset 22, 5, -7, 11, 2, 11?
A. 5. B. 7. C. 29. D. 4.
- Assuming that the dataset 22, 5, -7, 11, 2, 11 is a population, what is the population variance? A. 6. B. 7. C. 80. D. 41.
- For a skewed distribution, what is the minimum percentage of the observations that will lie within 2.5 standard deviations of the mean based on Chebyshev's rule? A. 84% B. 75% C. 78% D. 95%
- Compared to the formula for determining the population variance, the formula for determining the sample variance is. A. exactly same B. totally different C. similar except for ( n - 1 ) in the denominator instead of N D. similar except for ( n + 1 ) in the denominator instead of^ N
- If the z-score of an observation in a set of normally distributed numerical data is bigger than zero, it means that the observation is. A. an error B. an outlier C. bigger than the mean D. bigger than the standard deviation
- The coefficient of variation of a set of numerical data is.
A. the ratio of the mean to the variance expressed as a percentage B. the ratio of the mean to the standard deviation expressed as a percentage C. the ratio of the standard deviation to the variance expressed as a percentage D. the ratio of the standard deviation to the mean expressed as a percentage
- Scores obtained by students in an advanced placement test has a symmetric mound shaped (bell shaped) distribution with a mean of 70 and a standard deviation of 10. What is the proportion of students who received between 60 and 80 points. A. about 68% B. about 95% C. about 99.7%
D. not enough information
- For the previous problem, what is the proportion of students who received less than 50 points? A. 2.35% B. 3% C. 2.5% D. not enough information
- For the previous problems, what will your answer be for the proportion of the students who received less than 50 points, if the distribution is not symmetric and bell-shaped A. less than 12.5% B. less than 25% C. 2.5% D. not enough information
- What is the range for the following five numbers? 223, 264, 216, 218, 229
A. 22 B. 48 C. 29 D. 84 E. 46
- If the standard deviation of a population is 3, the population variance is.
A. 3 B. 9 C. 21 D. 27 E. 81
- If the sample variance of a dataset of size 8 is 2.57, what is the population variance if considering the same dataset to be a population?
D. 46.0%
E. 54.0%
- The mean of a distribution is 13, the median is 15, and the mode is 18. It is most likely that this distribution is. A. negatively skewed B. positively skewed C. symmetrical D. asymptotic E. leptokurtic
- The mean of a disitribution is 18, the median is 15, and the mode is 13. It is most likely that this distribution is. A. negatively skewed B. positively skewed C. symmetrical D. asymptotic E. leptokurtic
- Which one of the following is not used in developing a box and whisker plot to describe the distribution of data? A. the median B. the mean C. the lower quartile D. the upper quartile E. the smallest value within the inner fence
- Two measures of the shape of the distribution of a set of data are.
A. mean and standard deviation B. median and variance C. correlation and coefficient of variation D. skewness and kurtosis
- If the shape of the distribution of a set of data is positively skewed, its skewness is. A. positive B. zero C. negative D. infinity
- Box-and-whisker plot is a way to describe a distribution of data by using . A. a histogram and turning it horizontally B. a stem-and-leaf plot and turning it vertically C. four quartiles and placing one at each corner of a box D. three quartiles and two extreme values
- For a set of data with a distribution skewed to the left.
A. the mean is equal to the median B. the mean is lower than the median C. the mean is greater than the median D. the median is greater than the mean
- In the box and whisker plot, the length of the box is equal to.
A. the range B. the inter-quartile range C. 1.5 times the inter-quartile range D. the median
- A city police officer using radar checked the speed of 26 cars as they were travelling down a city street and the data is given as below: 27 23 22 38 43 24 25 23 22 54 31 30 29 48 27 25 29 28 26 33 25 21 23 34 20 23 it is most like that the distribution of the dataset is. A. negatively skewed B. positively skewed C. symmetrical D. asymptotic E. leptokurtic
