Chapter 12 - Data Analysis and Probability - 12-7 Theoretical and Experimental Probability - Practice and Problem-Solving Exercises - Page 774: 42

$\frac{3}{10}$

P(event)=$\frac{numberoffavorableoutcomes}{numberofpossibleoutcomes}$ The number of favorable outcomes is 3 of blue, so it will be the number of outcomes for finding the probability. P(event)=$\frac{numberoffavorableoutcomes}{numberofpossibleoutcomes}$ P(blue)=$\frac{3}{3+7}$ -simplify- P(blue)=$\frac{3}{10}$