1. Solve the following problem A group of 268 overweight people signed up for a weight loss program. Participants were asked to choose whether they wanted to go on a vegetarian diet or follow a traditional low-calorie diet that included some meat. 153 people chose the vegetarian diet, and the rest chose to be in the control group and continue to eat meat. There was a greater weight loss in the vegetarian group.
a. Identify the variables in the study and what types of variables they are.
b. What percentage of people was in the vegetarian group? What percentage was in the meat group? (Round to the nearest percent.)
c. What additional confounding variables might account for the increased weight loss in the vegetarian group? Explain.
d. Describe a better way to design the study that is more likely to remove the effect of confounding variables.
2. olve the following problem, and post your solutions to the discussion forum. Make your first post by Tuesday:
Jose asked a group of students to hold their breath as long as possible, and he recorded the times in seconds. Jose displayed the data in both a histogram and a stemplot, shown here.
Histogram of Breath Holding Data
describe the data by answering the following questions:
- What are the minimum and maximum data values?
- How many people participated in Jose’s experiment?
- Are there any outliers?
- Is the distribution symmetric or skewed?
- Which data value is most common?
- What is the middle value of the data?
- Which graph is easier to interpret? Why?
3. Think about the following questions and write your answer
- Which do you think is larger, the mean number of siblings of people in this class, or the median number of siblings? Justify your answer.
- How would you verify your answer to #1? What questions would you need to ask?
- What variables might account for the difference between the median and the mean?
Click here for things to keep in mind as you complete this discussion [PDF file size 389 KB].