what you’ll need to know:
In this support activity you’ll become familiar with the following:
- Use a research study description to answer questions.
You will also have an opportunity to refresh the following skills:
- Calculating proportions as percentages.
Throughout this class, you will need to compute fractions, proportions, and percentages and convert from one representation to another. You practiced these skills in the Corequisite Support Activity 1C and 1E. Also See the student resources [link to student resource: Fractions, Decimals, Percentages] and [link to student resource: Rounding and Estimation] as needed for additional assistance.
Reading Data from Tables
Take some time individually to read the scenario given in Question 1. If you finish before others, begin working at your own pace to answer the questions. Once others nearby have begun working, you can work together to complete the activity. As you complete these questions, you may need to refresh your arithmetic skills using the Recall box.
recall
Core skill:
question 1
Read the study and answer the questions that follow.
Researchers wanted to know whether adults who attended a 45-minute spin class two days per week and a 30-minute cross-training class two days per week met the guidelines set forth by the American Heart Association (AHA) for physical activity.
For adults to maintain good overall cardiovascular health, the AHA recommends 150 minutes per week of moderate exercise at a minimum of 70% of a person’s maximum heart rate.
To investigate, 21 adults were given heart rate monitors to wear every day for a two-week period while they attended the spin and cross-training classes. Each person’s heart rate was recorded, and then an average heart rate while exercising was computed and converted to a percentage based on their maximum heart rate. The results are shown in the table below.
| Average Heart Rate (H) as a Percentage of Maximum Heart Rate | Number of Adults |
| H less than 50% | 3 |
| H between 50% and 70% | 5 |
| H at or above 70% | 13 |
Part A: What proportion of the participants met the AHA guidelines? Express your answer as a decimal rounded to the nearest hundred-thousandth (5 decimal places).
Part B: Convert the proportion in Part A to a percentage rounded to the nearest tenth.
Part C: Convert the proportion in Part A to a percentage rounded to the nearest whole percentage point.
Part D: What proportion of the participants averaged 50–70% of their maximum heart rate? Express your answer as a decimal rounded to the nearest hundred-thousandth (5 decimal places).
Part E: Convert the proportion in Part D to a percentage rounded to the nearest tenth.
Part F: Convert the proportion in Part D to a percentage rounded to the nearest whole percentage point.
Part G: What proportion of the participants averaged below 50% of their maximum heart rate? Express your answer as a decimal rounded to the nearest hundred-thousandth (5 decimal places).
Part H: Convert the proportion in Part G to a percentage rounded to the nearest tenth.
Part I: Convert the proportion in Part G to a percentage rounded to the nearest whole percentage point.
In this support activity, you had a chance to practice converting proportions to percentages and refreshed your skills for rounding to a desired percentage point. The Student Resources Fractions, Decimals, Percentages and Rounding and Estimation will provide more support if you need it. Let's move on to the next What to Know page to learn about observational studies.
