Esmeralda Rose MT 256 Probability and Statistics Fall 2022 S. Pustejovsky Problem Set 1 You may answer these questions on this paper and submit to the Moodle folder in Week 4. OR You may hand-write your answers and submit a hard copy on Monday next week. NOTE: This looks a lot longer than it actually is. ---------------------------Criteria: A successful performance shows that you are able to: 1. Identify individuals (also called “observational units” or “cases”) and variables correctly, along with variable types, in a given study. 2. Identify a research question in a given study. 3. Interpret plots of data appropriately 4. Produce appropriate plots of given data, and answer questions about them. ----------------------------Problems See next page MT 256 Probability and Statistics Fall 2022 S. Pustejovsky Problem Set 1 1. This is a study from an exercise in another textbook: a. Identify the individual observational units (cases) in this study. Men and women, and whether they washed their hands after using the bathroom b. Identify three variables that were recorded, along with what type of variable each is (categorical or quantitative). - People’s gender: Categorial (Could be quantitative 0,1) If they washed their hands: Categorical (Could be quantitative 0,1) Location: Categorical c. Here is a graph of some of the data, and some questions about the graph. · What type of graph (chart) is this (for example: bar graph, histogram, pie chart)? This is a bar graph · What is a research question that may be addressed with the data shown in this graph? Which gender is more likely to wash their hands after using the bathroom? MT 256 Probability and Statistics Fall 2022 S. Pustejovsky Problem Set 1 2. Some college students were asked how many body piercings they had. Results are shown in the two graphs below – one is a dot plot and the other is a histogram. a. How many students had only one piercing? Which graph must you use to determine this? 5 students had only one piercing. We need to use the dot plot. b. In the histogram, there is bin that is between 6 and 8 on the horizontal axis. The height of this bin is 6. Where did this height of 6 come from? Use the dot plot to help you figure this out. The height of 6 is from adding the 5 responses from 6 piercings and the one response from 7 piercings. c. What is the height of the right-most bin? Explain. I looked at the histogram and guessed it was about 35, then I counted the dots on the dot plot and it was actually 31. MT 256 Probability and Statistics Fall 2022 S. Pustejovsky Problem Set 1 3. How much fruit do teen girls eat? Below is a histogram created from a survey of 74 adolescent girls, age 17. Describe the shape of the histogram. This histogram is skewed right. Find the median of the data. 4 4 4 5 7 11 11 15 15 What percent of these girls ate 6 or more servings of fruit per day? About 5% How many girls at fewer than 2 servings per day? About 34% MT 256 Probability and Statistics Fall 2022 S. Pustejovsky Problem Set 1 Compute a 5-number summary and use it to produce a hand-drawn box plot of this data. It might be easier to do this on a grid (see next page). Maximum = 15 Q3 = 13 Median = 7 Q1 = 4 Minimum = 4
