options: Develop understanding of statistical variability.

Investigate chance processes and develop, use, and evaluate probability models.

Draw informal comparative inferences about two populations.

Summarize, represent, and interpret data on a single count or measurement variable.

Summarize, represent, and interpret data on two categorical and quantitative variables.

Understand independence and conditional probability and use them to interpret data.

Interpret linear models.

Use probability to evaluate outcomes of decisions.

Understand and evaluate random processes underlying statistical experiments.

Use the rules of probability to compute probabilities of compound events in a uniform probability model.

Calculate expected values and use them to solve problems.

Investigate patterns of association in bivariate data.

Make inferences and justify conclusions from sample surveys, experiments, and observational studies.

Summarize and describe distributions.

Use random sampling to draw inferences about a population.
problem_activity: Task
Ari has collected data on how much her classmates study each week and how well they did on their recent math test. Here is part of the data, showing the percentage of each group (divided according to hours spent studying) who got different grades on the test:
| Weekly Hours $w$ Studying | C or below on test | B on test | A on test |
|---------------------------|--------------------|-----------|-----------|
|         $w \lt$ 3         |        50%         |    20%    |    30%    |
|     $3 \leq w \lt 6$      |        60%         |    25%    |    15%    |
|        $w \geq 6$         |        60%         |    20%    |    20%    |
What can you conclude about the percentage of Ari's classmates who got B's? What about the percent who got A's?
Looking at the table, Ari decides that in order to do well in her math class, she should not study more than 3 hours a week: she has a 30 percent chance of getting an A as long as she does not study more than 3 hours per week. Is Ari's reasoning valid?


correct_option_index: 6