Back to Construct and interpret two-way frequency tables — Problem 2 · Task Set 21

Exercises: Construct and Interpret Two-Way Frequency Tables

Work through each section in order. Read each two-way table carefully and
decide which total is the correct denominator BEFORE computing: the grand
total for marginal and joint probabilities, but a single row or column total
for a conditional probability. Write probabilities as fractions or decimals,
and remember that probabilities read from sample data are ESTIMATES, not
exact values.

Grade 10·21 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-cp-a-4
Work through problems with immediate feedback
A

Fluency Practice

Compute each probability from the given table. Choose the correct denominator before you compute.

1.

Use the favorite-subject table.

MathScienceEnglishTotal
10th grade18241860
11th grade22162260
Total404040120

Find the JOINT probability P(eleventh grade and favors math)P(\text{eleventh grade and favors math}) for a randomly selected student. Give your answer as a fraction in lowest terms.