Prepare for your exams

Study with the several resources on Docsity

Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips

Prepare for your exams

Study with the several resources on Docsity

Earn points to download

Earn points by helping other students or get them with a premium plan

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

MATH225N Week 4 Statistics Quiz-with 100% verified solutions Week 4 quiz .docx

Typology: Exams

2023/2024

1 / 19

Download MATH225N Week 4 Statistics Quiz-with 100% verified solutions Week 4 quiz .docx and more Exams Mathematics in PDF only on Docsity! MATH225N Week 4 Statistics Quiz-with 100% verified solutions 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 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: That is correct! Answer: 16 Boxes That is correct! Answer: median=26 thousands of dollars That is correct! Answer: mode=3 cards Mean: 104.25; Median: 92.5; Mode: 98. Identify the outlier and the measure of central tendency that is affected by the outlier. 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? 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 That is correct! Answer: Std 3.1 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 A random sample of house sizes in major city has a sample mean of x¯=1204.9 sq ft and sample standard deviation of s=124.6 sq ft. Use the Empirical Rule to determine the approximate percentage of house sizes that lie between 955.7and 1454.1 sq ft. Round your answer to the nearest whole number (percent). Answer: 95 % That is correct! That is correct! Question 10 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 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 Students Go to the mounta i ns do not go to the mountains Tot a l Go to the beach 36 Do not go to the beach 21 Total 48 95 That is correct! Answer: 10 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 heights. The data are shown in the contingency table below. What is the relative risk of being afraid of heights for those who are afraid of flying? Round your answer to two decimal places. Afraid of heights Not afraid of heights Total Afraid of flying 76 33 109 Not afraid of flying 82 370 452 Total 158 403 561 Answer: 3.84 Question 17 Which of the following frequency tables show a skewed data set? Select all answers that apply. That is correct! Value Frequency 5 1 6 2 7 10 8 11 9 17 10 17 11 15 12 12 13 7 14 7 15 0 16 1 Value Frequency That is correct! 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. 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. The data is not 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. Question 21 Find the mode of the following amounts (in thousands of dollars) in savings accounts of randomly selected people aged 25-30. 8,6,8,7,2,2,2,4,4,4,4,7 Answer: 92.3 That is correct! That is correct! That is correct! That is correct! Question 22 A deck of cards contains red cards numbered 1,2,3,4,5, blue cards numbered 1,2,3,4,5,6,7,8 and green cards numbered 1,2,3,4,5,6,7,8,9,10. If a single card is picked at random, what is the probability that the card is green? • Give your answer as a fraction. • • That is correct! • Answer: 10/23 Question 23 The five-number summary for a set of data is given below. Min Q1 Median Q3 Max 60 6 5 70 7 87 5 What is the interquartile range of the set of data? 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? Answer: Mode = 4 thousands of dollars That is correct! That is correct! Answer: Interquartile range is 10