8.2 relative frequency homework answers

1. Data was collected for 300 fish from the North Atlantic. The length of the fish (in mm) is summarized in the GFDT below. Lengths (mm) Frequency 100 - 102 1 103 - 105 16 106 - 108 71 109 - 111 108 112 - 114 83 115 - 117 18 118 - 120 3 What is the lower class boundary for the first class? class boundary = 2. 50 part-time students were asked how many courses they were taking this term. The (incomplete) results are shown below: # of Courses Frequency Relative Frequency Cumulative Frequency 1 18 2 18 0.36 3 18 Correct 50 Correct a. Complete the table. b. What percent of students take exactly three courses? % 3. Ages 15-18 19-22 23-26 27-30 31-34 35-38 Number of students 9 10 2 8 3 3 Find the relative frequency for the class with lower class limit 23 Relative Frequency = % Give your answer as a percent, rounded to two decimal places 4. The following data represents the age of 30 lottery winners. 23 28 31 32 34 36 37 38 39 42 43 50 52 54 54 54 55 59 61 62 66 68 68 75 77 78 78 78 79 82 Complete the frequency distribution for the data. Age Frequency 20-29 30-39 40-49 50-59 60-69 70-79 80-89 5. In a student survey, fifty-two part-time students were asked how many courses they were taking this term. The (incomplete) results are shown below: Please round your answer to 4 decimal places for the Relative Frequency if possible. # of Courses Frequency Relative Frequency Cumulative Frequency 1 14 2 12 0.2308 3 26 0.5 What percent of students take exactly one courses? 52 % 6. Identify the type of data that would be used to describe a response. Number of tickets sold to a concert • Qualitative (Categorical) • Quantitative - Discrete • Quantitative – Continuous 7. Determine if the following is an example of descriptive or inferential statistics. A hospital administrator wants to see if fewer mistakes are made if nurses are forced to take frequent breaks. After observing a sample of 300 nurses who were not forced to take frequent breaks and 400 who were forced to take frequent breaks, it was clear from the data that implementing a policy to force nurses to take frequent breaks will decrease the average number of mistakes. • Inferential Statistics • Descriptive Statistics 8. A state university is interested in where its students come from. They survey 300 of its students to find out if they are in-state, out-of-state, or foreign students. Match the vocabulary word with its corresponding example. • - The list of the 300 answers to the survey question • - The proportion of the 300 surveyed students who are in-state students • - The answer in-state out-of-state or foreign • - The proportion of all students from this university who are in-state students • - All students at the university • - The 300 students who were surveyed a. Data b. Statistic c. Population d. Sample e. Variable f. Parameter 9. A rancher is interested in the average age that a cow begins producing milk. Match the vocabulary word with its corresponding example. • - The list of the 62 ages • - The average age for the 62 observed milk cows as they first produced milk • - All milk cows • - The average age that all milk cows are when they first produce milk • - The 62 milk cows that were observed by the rancher • - The age when a milk cow first produced milk a. Population b. Parameter c. Variable d. Sample e. Data f. Statistic 10. Suppose you want to estimate the percentage of videos on YouTube that are cat videos. It is impossible for you to watch all videos on YouTube so you use a random video picker to select 1000 videos for you. You find that 2% of these videos are cat videos. Determine which of the following is an observation, a variable, a sample statistic, or a population parameter. a) The percentage of all videos on YouTube that are cat videos is a/an: • sample statistic • observation • population parameter • variable b) 2% is a/an • observation • sample statistic • variable • population parameter c) A video in your sample is a/an • population parameter • observation • variable • sample statistic d) Whether or not a video is a cat video a/an • observation • sample statistic • population parameter • variable 11. A researcher is interested in attitudes towards releasing prisoners with Alzheimer's who have a life sentence. 85 randomly selected Americans were asked, "Prisoners with Alzheimer's who have a life sentence should be released: Strongly Agree, Agree, Disagree, Strongly Disagree". Match the vocabulary word with its corresponding example.