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Solutions to various questions related to statistics, including finding means, medians, modes, and outliers in given datasets. It also covers topics such as skewed data, variance, standard deviation, and the empirical rule. Additionally, it discusses concepts like independence, relative risk, and contingency tables.

Typology: Exams

2023/2024

1 / 22

Download Statistics Quiz Solutions for Week 4 Math 225N and more Exams Statistics in PDF only on Docsity! pg. 1 1 WEEK 4 MATH 225N STATISTICS QUIZ Week 4 quiz QUESTION 1 Alice sells boxes of candy at the baseball game and wants to know the mean number of boxes she sells. The numbers for the games so far are listed below. 16,14,14,21,15 Find the mean boxes sold. QUESTION 2 Given the following list of prices (in thousands of dollars) of randomly selected trucks at a car dealership, find the median. 20,46,19,14,42,26,33 QUESTION 3 Each person in a group shuffles a deck of cards and keeps selecting a card until a queen appears. Find the mode of the following number of cards drawn from a deck until a queen appears. 3,12,3,11,5,5,3,10,12 That is correct! Answer: 16 Boxes That is correct! Answer: median=26 thousands of dollars pg. 2 2 QUESTION 4 The dataset below represents bugs found by a software tester in her product during different phases of testing: 88, 84, 81, 94, 91, 98, 98, 200. The measures of central tendency are given below: Mean: 104.25; Median: 92.5; Mode: 98. Identify the outlier and the measure of central tendency that is affected by the outlier. That is correct! Answer: mode=3 cards pg. 5 5 QUESTION 6 The following data set represents the ages of all seven grandchildren in a family. 4, 5, 11, 12, 11, 8, 5 If the variance of the ages is 9.7, what is the standard deviation? • Round the final answer to one decimal place. QUESTION 7 Which of the data sets represented by the following box and whisker plots has the smallest standard deviation? That is correct! Answer: Std 3.1 pg. 6 6 Four horizontal box-and-whisker plots share a vertical axis with the classes D, C, B, and A and a horizontal axis from 0 to 120 in increments of 20. The box-and-whisker plot above the class label A has the following five-number summary: 44, 69, 77, 82, and 112. The box-and-whisker plot above the class label B has the following five-number summary: 19, 64, 78, 87, and 121. The box-and-whisker plot above the class label C pg. 7 7 has the following five-number summary: 60, 72, 75, 80, and 92. The box-and-whisker plot above the class label D has the following five-number summary: 2, 63, 77, 92, and 138. All values are approximate. A B C D QUESTION 8 The box-and-whisker plot shows the number of books read by history students during the last school year. A box and whisker plot with minimum 4, first quartile 6, median 8, third quartile 10, and maximum 15 What is the range of the data? That is correct! Answer: 11 QUESTION 9 That is correct! pg. 10 10 QUESTION 13 Of the following pairs of events, which pair has mutually exclusive events? rolling a sum greater than 7 from two rolls of a standard die and rolling a 4 for the first throw drawing a 2 and drawing a 4 with replacement from a standard deck of cards That is correct! Answer: 73/80 That is correct! pg. 11 11 rolling a sum of 9 from two rolls of a standard die and rolling a 2 for the first roll drawing a red card and then drawing a black card with replacement from a standard deck of cards QUESTION 14 Fill in the following contingency table and find the number of students who both go to the beach AND go to the mountains. QUESTION 15 Students Go to the mountai ns do not go to the mountains Tota l Go to the beach 36 Do not go to the beach 21 Total 48 95 That is correct! Answer: 10 pg. 12 12 A group of 140 students at an elementary school were asked if they prefer the color orange to the color green. The results are shown in the table below. Given that a randomly selected survey participant is a male, what is the probability that this student prefers the color green? • Enter your answer as a fraction. Male Female Tota l Orange 12 50 62 Green 2 73 78 Total 17 123 140 That is correct! Answer: 5/17 QUESTION 16 Researchers want to study whether or not a fear of flying is related to a fear of heights. They surveyed a large group of people and asked them whether or not they had a fear of flying and whether or not they had a fear of pg. 15 15 6 3 7 8 8 10 9 13 10 26 11 14 12 12 13 8 14 3 15 1 16 1 Value Frequency 12 1 13 1 14 3 15 6 16 23 17 29 18 19 19 15 20 3 pg. 16 16 Value Frequenc 5 1 16 2 23 3 19 4 22 5 9 6 4 7 2 QUESTION 18 A student wants to know his average homework grade for the first half of his math class. There were 7 homeworks in the first half of the class, and his grades out of 100 are given by 100,90,95,89,92,85,95. What is the population mean of his homework grades? Round your answer to the nearest tenth. pg. 17 17 QUESTION 19 The following data set represents the ages of all six grandchildren in a family. Find the variance for this data set of ages: 6, 3, 14, 11, 14, 6 • Round the final answer to one decimal place. Answer: Variance = 18 QUESTION 20 A poll was conducted during the final game of the basketball season to determine whether fans wanted to see the defending champions win the game or the challenging team win the game. From the poll, 216 of the 374 residents sampled from urban areas want the defending champions to win the game. In more rural areas, 304 of the 466 residents polled want the defending champions to win the game. Assuming location has nothing to do with team preference, the probability that the data gathered was the result of chance is calculated to be 0.03. What is the correct interpretation of this calculation? More people from rural areas want the defending champions to win the game. Exactly 216 out of every 374 urban residents want the defending champions to win the game. The results are statistically significant at the 0.05 level of significance in showing that the proportion of people in rural areas who want the defending champions to win the game is different than the proportion of people in urban areas. Answer: 92.3 That is correct! That is corre t! That is correct! pg. 20 20 QUESTION 24 The five-number summary for a set of data is given below. Min Q1 Median Q3 Max 43 4 7 53 6 72 2 What is the interquartile range of the set of data? That is correct! Answer: Interquartile range is 10 pg. 21 21 QUESTION 25 The following frequency table summarizes a set of data. What is the five-number summary? Value Frequency 3 3 5 2 10 1 13 1 14 3 15 3 16 1 20 1 MIN Q1 MEDIAN Q3 MAX 3 5 9 15 20 Answer: Interquartile range is 15 That is correct! That is correct! pg. 22 22 MIN Q1 MEDIAN Q3 MAX 3 10 11 17 20 MIN Q1 MEDIAN Q3 MAX 3 5 14 15 20 MIN Q1 MEDIAN Q3 MAX 3 6 18 17 20 MIN Q1 MEDIAN Q3 MAX 3 6 7 14 20