Big Ideas Math Geometry, 2014
BI
Big Ideas Math Geometry, 2014 View details
3. Two-Way Tables and Probability
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Exercise 8 Page 688

Divide each joint frequency by the grand total to obtain the joint relative frequencies. Divide each marginal frequency by the grand total to obtain the marginal relative frequencies.

Gender
Experience Male Female Total
Expert 0.151 0.015 0.166
Average 0.671 0.058 0.729
Novice 0.098 0.007 0.105
Total 0.920 0.080 1
Practice makes perfect
Consider the two-way table that we are given.
Gender
Experience Male Female Total
Expert 62 6 68
Average 275 24 299
Novice 40 3 43
Total 377 33 410

We want to use this table to construct a two-way table that shows the joint and marginal relative frequencies. To do so, we will divide each joint frequency by the grand total to obtain the joint relative frequencies. Similarly, we will divide each marginal frequency by the grand total to obtain the marginal relative frequencies.

Gender
Experience Male Female Total
Expert 62/410 ≈ 0.151 6/410 ≈ 0.015 68/410 ≈ 0.166
Average 275/410 ≈ 0.671 24/410 ≈ 0.058 299/410 ≈ 0.729
Novice 40/410 ≈ 0.098 3/410 ≈ 0.007 43/410 ≈ 0.105
Total 377/410 ≈ 0.920 33/410 ≈ 0.080 410/410 = 1