Calculations Distribution

6/4/2018 PRINTABLE VERSION Quiz 1 Question 1 True or False: The amount of rainfall in your state last month is an example of discrete data. a) True b) False Question 2 True or False: The standard deviation is the square of the variance. a) True b) False Question 3 Which of the following is not affected by an extreme value in the data set? a) standard deviation b) range c) median d) mean Question 4 Given a data set of all positive values, if the smallest value of a data set is divided by two, which of the following is true? a) The interquartile range increases. b) The standard deviation decreases. c) The range decreases. 1/5 6/4/2018 d) The mean decreases. Question 5 If the test scores of a class of 35 students have a mean of 71.1 and the test scores of another class of 28 students have a mean of 67.4, then the mean of the combined group is a) 67.750 b) 69.250 c) 69.456 d) 66.956 Question 6 Given the first type of plot indicated in each pair, which of the second plots could not always be generated from it? a) dot plot, histogram b) stem and leaf, dot plot c) histogram, stem and leaf d) dot plot, box plot Question 7 A survey was conducted to gather ratings of the quality of service at local restaurants. Respondents rated on a scale of 0 (terrible) to 100 (excellent). The data are represented by the following stem plot. The median response was a) 50 b) 51 c) 51.5 d) 52 2/5 6/4/2018 Question 8 Calculate the mean, median, mode, range and standard deviation of the data: -5, -1, -1, 3, 9 a) mean = 1.0, median = -1, mode = -1, range = 14, standard deviation = 5.3 b) mean = 1.8, median = -5, mode = -1, range = 13, standard deviation = 5.2 c) mean = 1.0, median = 3, mode = -5, range = 15, standard deviation = 5.3 d) mean = 1.8, median = -1, mode = -1, range = 14, standard deviation = 5.2 e) None of the above Question 9 Calculate the mean, median, mode, range and standard deviation of the data: -72, -40, -40, 56, 88 a) mean = -1.6, median = 56, mode = -72, range = 161, standard deviation = 69.4 b) mean = -1.6, median = -40, mode = -40, range = 160, standard deviation = 69.4 c) mean = 17.6, median = -40, mode = -40, range = 160, standard deviation = 69.4 d) mean = 17.6, median = -72, mode = -40, range = 159, standard deviation = 69.4 e) None of the above Question 10 The boxplots shown below summarize two data sets, I and II. Based on the boxplots, which of the following statements about these two data sets CANNOT be justified? a) The interquartile range of data set I is equal to the interquartile range of data set II. b) Data set I and data set II have the same number of data points. c) The range of data set I is greater than the range of data set II. d) The median of data set I is equal to the median of data set II. 3/5 6/4/2018 Question 11 The distribution that has the box plot shown could be described as a) skewed left b) skewed right c) symmetrical d) inconclusive Question 12 The figure below shows a cumulative relative frequency plot of 40 scores on a test given in a Statistics class. Which of the following conclusions can be made from the graph? The horizontal nature of the graph for test scores of 60 and below indicates that those scores occurred a) most frequently. 4/5 6/4/2018 b) There is greater variability in the lower 20 test scores than in the higher 20 test scores. c) The median test score is less than 70. d) Sixty percent of the students had a test score above 80. Question 13 The weights of male and female students in a class are summarized in the following boxplots: Which of the following is NOT correct? a) About 50% of the male students have weights between 150 and 185 lbs. b) About 75% of the female students have weights more than 128 lbs. c) The mean weight of the female students is about 120 because of symmetry. d) The median weight of the male students is about 166 lbs. Question 14 Given a data set consisting of 33 unique whole number observations, its five-number summary is: What is the IQR? a) 45 b) 22 c) 23 d) 46 5/5