Lesson 3

Associations and Relative Frequency Tables

  • Let’s explore relative frequency tables

3.1: Estimation

What percentage of the graph is labeled C?

Circle divided into sections. A and B are same size, each about 33% of circle. C, D, and E are same size and together take up rest of circle 
  1. Record an estimate that is:
     too low  about right   too high 
         
  2. Explain your reasoning.

3.2: Relative Frequency Tables

The relative frequency tables display data collected from 230 students. 

  1. participates in afterschool activity  no afterschool activity  total
    arrives home within 2 hours of school dismissal 3% 40% 43%
    arrives home 2 or more hours after school dismissal 42% 15% 57%
    total 45% 55% 100%
    1. What percentage of students participate in after-school activities? How many students participate in after-school activities?
    2. What percentage of students arrive home 2 or more hours after dismissal? How many students arrive home 2 or more hours after school dismissal?
  2.  aspiring professional athlete  aspiring STEM career  total
    prefer physical education 77% 23% 100%
    prefer math  18% 82% 100%
    1. What percentage of students who prefer math aspire to have a career in STEM?
    2. What percentage of students who prefer physical education aspire to have a career in STEM?
    3. Are these two percentages close?
    4. Is there evidence of an association between students’ career aspirations and subject preference? Explain your reasoning.
  3.  9th grade 12th grade
    curfew 95% 90%
    no curfew 5% 10%
    total 100% 100%
    1. Of the students in 12th grade, what percentage have a curfew?
    2. Of the students in 9th grade, what percentage have a curfew?
    3. Is there evidence of an association between students’ grade level and whether they have a curfew? Explain your reasoning.

3.3: Associate Your Variables

  1. Invent a pair of variables that you think will have an association. Explain your reasoning.
  2. Invent a pair of variables that you think will not have an association. Explain your reasoning.

Summary