Download MATH 225N Week 2 Statistics Quiz and more Exams Mathematics in PDF only on Docsity! MATH 225N Week 2 Statistics Quiz.LATEST 2023 WEEK 2 MATH 225N STATISTICS Question 1 A company has developed a wristband for monitoring blood sugar levels without requiring direct blood samples. It is interested in demonstrating the accuracy of the device for governmental approval and has decided to test the claim "The glucose level reported by the wristband is within 10% of a standard blood test result." Which of the following data collection processes would be appropriate? Select only one answer choice. Choose a random sample of employees at lunchtime and measure their blood sugar using both the wristband and a standard blood test. Choose a random sample of people from the local area and random times throughout the day and measure their blood sugar using both the wristband and a standard blood test. Choose a random sample of people from the local area and random times and measure their blood sugar using the wristband. Choose another random sample of people and random times and measure their blood sugar using the standard blood test. Go to a hospital and have the doctors choose a random sample of patients to be tested at random times using both the wristband and the standard blood test. Question 2 A farmer divided his piece of land into 4 equivalent groups. The quality of the soil is the same across the 4 groups of land. He planted the same crop in all 4 groups of land and recorded the yield of the crop in all 4 groups for a 4 week period. Is the study observational or experimental? If it is an experiment, what is the controlled factor? The study is an observational study. The study is an experiment. The controlled factor is the 4 week observation period. The study is an experiment. The controlled factor is the land. The study is an experiment. The controlled factor is the growth of the crops. That is correct! Question 3 To test the effectiveness of a drug proposed to relieve symptoms of headache, physicians included participants for a study. They gave the drug to one group and a drug with no therapeutic effect to another group. Which group receives the placebo? the specific number of siblings for each randomly selected student all the students in the school the mean number of siblings for the randomly selected students the mean number of siblings for all students in the school Question 8 True or False? In reference to different sampling methods, systematic sampling includes the steps: divide the population into groups; use simple random sampling to identify a proportionate number of individuals from each group. True Fals e Question 9 While standing on a highway overpass, Jennifer wonders what proportion of the vehicles that pass on the highway below are trucks. The highway has 4 lanes running in each direction. Jennifer is only interested in the proportion of vehicles that pass over the course of the hour that she spends there. Which of the following sampling methods would be best for Jennifer to employ? Obtain a cluster sample by randomly selecting 3 of the 36 numbers and letters that might be at the beginning of a license plate, and select every vehicle whose license plate starts with one of those 3 numbers or letters. Obtain a convenience sample by watching 1 lane and selecting every vehicle that passes in that lane. Obtain a systematic sample by selecting every 20 th vehicle that passes (in any lane and going in any direction). Obtain a stratified sample by, during every minute, spending 712 second watching each of the 8 lanes and selecting the last vehicle that passes during the time it is being watched (or the first vehicle after that time if no cars pass during that time). Question 10 As a member of a marketing team, you have been tasked with determining the number of DVDs that people have rented over the past six months. You sample twenty adults and decide that the best display of data is a frequency table for grouped data. Construct this table using four classes. the 200 randomly selected students That is correct! That is correct! 15,30,28,19,14,18,28,19,10,19,10,24,14,18,24,27,10,18,16,23 orrect answers: 1$10$10 Note that the data is not ordered and that we have been asked to use 4 classes. To determine the class width, use the formula: Max Value−Min ValueNumber of Classes=30−104=5. Since this value is an integer, there is no need to round. Use the minimum value, 10, for the lower class limit of the first class. To find all other lower class limits, add the class width, 5, plus 1. For example, the second lower class limit would be: 10+5+1=16. Lower Class Limit Upper Class Limit Frequency 10 16 22 28 To find the upper class limits, add the class width, 5, to each lower class limit. For example, the upper class limit of the first class would be: 10+5=15. Lower Class Limit Upper Class Limit Frequency 10 15 16 21 22 27 28 33 2$15$15 3$6$6 4$16$16 5$21$21 6$7$7 7$22$22 8$27$27 9$4$4 10$28$28 11$33$33 12$3$3 ® uniform
unimodal and symmetric unimodal and left-skewed unimodal and right- skewed bimodal Question 14 A set of data is summarized by the stem and leaf plot below. Ste m Lea f 1 0 0 2 4 4 4 7 8 8 8 8 9 2 2 2 5 5 7 8 3 3 4 4 5 5 5 6 6 6 7 9 9 There are 12 values in the data set which are greater than or equal to 10 and less than or equal to 19. There are 12 values in the data set which are greater than or equal to 30 and less than or equal to 39. There are 6 values in the data set which are greater than or equal to 20 and less than or equal to 29. Question 15 The bar graph below shows the number of boys and girls in different classes. That is correct! A bar graph has a horizontal axis labeled Classes and a vertical axis labeled Students from 0 to 16 in increments of 2. There are two vertical bars above each horizontal axis label, with the bar on the left representing Boys and the bar on the right representing Girls. The bars have heights as follows, with the horizontal axis label listed first and the bar heights listed second from left to right: Mrs. Brown, 10 and 15; Ms. James, 11 and 12. How many total students are in Ms. James's class? Do not include the units in your answer. Question 16 The line graph shown below represents the number of TVs in a house by square footage (in hundreds of feet). According to the information above, which of the following is an appropriate analysis of square footage and TVs? 23 That is correct! A side-by-side bar graph has a horizontal axis labeled Clubs with the classes Drama and Computer and a vertical axis labeled Students from 0 to 16 in increments of 2. Two vertical bars are above each horizontal axis label with the left bar representing Men and the right bar representing Women. The bars have heights as follows, with the horizontal axis label listed first and the bar height listed second: Drama, 11 and 16; Computer, 14 and 14. How many total students are in the Drama Club? Question 19 An English professor asks her students who their favorite character is in the novel they are reading. What is the level of measurement of the data? nomin al ordinal interva l ratio Question 20 Jessica is keeping track of her favorite stock's price. The line graph below shows the data. Answer: 27 Students That is correct! That is correct! A line graph titled Stock Price Over Time has a horizontal X-axis labeled Days from 0 to 5 in increments of 1 and a vertical Y-axis labeled Price from 0 to 14 in increments of 2. The graph consists of 6 plotted points connected by line segments from left to right. The coordinates of the plotted points are at left-parenthesis 0 comma 13 right-parenthesis, left-parenthesis 1 comma 3 right-parenthesis, left-parenthesis 2 comma 10 right- parenthesis, left-parenthesis 3 comma 4 right-parenthesis, left-parenthesis 4 comma 14 right- parenthesis, and left-parenthesis 5 comma 12 right-parenthesis. At what day was the price 10? Answer: day 2 That is correct! Question 21 A set of data is summarized by the stem and leaf plot below. 1 5 2 3 3 2 4 3 5 5 6 0 7 9 8 1 9 6 10 4 Give your answer as a single number. For example if you found the number of values was 23, you would enter 23. Question 24 Timothy wants to estimate the mean number of siblings for each student in his school. He records the number of siblings for each of 75 randomly selected students in the school. What is the statistic? the specific number of siblings for each randomly selected student the 75 randomly selected students the mean number of siblings for the randomly selected students the mean number of siblings for all students in the school all the students in the school Question 25 In a psychological study aimed at testing a drug that reduces anxiety, the researcher grouped the participants into 2 groups and gave the anxiety-reduction pill to one group and an inert pill to another group. Which group receives the placebo? Answer: 20 That is correct! That is correct! That is correct! the group that received the anxiety- reduction pill the psychological study all the people in the study the group that received the inert pill