Need help with these multiple choice question on Statistics
1. Clearly circle or indicate the letter corresponding to your choice. a) Suppose that you wanted to generate 100 observations from an Exponential[5{)] distribution, rounded to 2 decimal places. Which of the following R commands would you use? round[rexp[50,100], digits=2) rexp[[1{)0, 50), round = 2] round[rexp[100, 0.02], digits = 2] round[rexp[digits = 2], 100,1/50) More than one of these is correct ramps??- None of these are correct. [I] The following is a bar graph illustrating the lunch options, and the number sold at a local restaurant in a one-week period: Cafeteria Lunch Menu Number of Items Sold 95 3 15 65 '5 I I Caesar Salad Taco Wrao Sandwiches Soup Chicken Daily Special Burger Available Items Which of the following is true based on the above bar graph? A. The median choice was soup B. The average option was a taco wrap C. The distribution of lunch options is skewed to the left D. None of the above are true c] Suppose that you are given the following summary statistics for a random sample of n = 50 bivariate (x, y] observations: 1x, = 1,250 2?; y, = 3,100 15212:? = 45,000 1213;? = 250,000 1x,y, = UNKNOWN Izzy Abel, a Co-op student, has been assigned to analyze these data. He is unsure of the value for i521 xiyi, however, he has been told by his manager that a plot of the data has revealed a strong positive correlation between x and y. Based on this information, he has narrowed the value of Zfl xiy; down to one of 4 options. Which one is correct? A. 105,000 B. 125,000 C. 50,000 D. More than one ofthese is possible (1] Suppose that an observation, [x,y]=[25, 62) was removed from the original set of data from part c) of this question. How would this affect the mean and standard deviation for x and y, respectively? A. Means would be unaffected; standard deviations would decrease B Both means would increase; standard deviations would be unaffected C. Both means would decrease; standard deviations would increase D Means would be unaffected; standard deviations would increase e] Consider a data set with 31 observations. It has a sample median of 45. Two additional observations: 40 and 63 are added to the data set. What is the median of the sample of 33 observations? A. 42.5 B. 51.5 C. 45 D. Cannot be determined f] A relative frequency histogram of 96 observations has unequal intervals. There are 12 observations in the interval [160, 175]. What is the height ofthe rectangle above the interval [160, 175]? A. 0.8 B. 12 C. 0.0083 D. 0.125 h] Suppose that a sample, yI, yz, yg, y; has y; 5y; 5y3 5y4. The mean of the sample is 63, the median is 60, and the range is 44-. What is the value of y1? A. 92 B. 4-6 C. 4-4 D. Cannot be determined i] You are given the following side-byside boxplots for 2 different data sets: Actual weights of universitystudents Gender ale Female 4D 5 I3 SCI 1 CID 1 2|] Act wl weight (k 9) Which of the following statements is / are TRUE? (1) The [QR of females is greater than the [QR of males ([1] The median of females is less than the lower quartile of males A. Neither statements are true B. (1] only C. (11] only D. Both statements are true
