Exercise 4 Page 370

When calculating probability, we are comparing the number of favorable outcomes to the number of possible outcomes. To calculate the probability that a coin will land heads up we will use the Probability Formula. P=Favorable Outcomes/Possible Outcomes A coin has two sides. This means that the number of possible outcomes is 2. Because only one side of a coin is heads, the number of favorable outcomes is 1. Now we have enough information to calculate P(heads).

P=Favorable Outcomes/Possible Outcomes

SubstituteValues

Substitute values

P(heads)=1/2

ExpandFrac

a/b=a * 50/b * 50

P(heads)=50/100

WritePercent

Convert to percent

P(heads)=50 %

The probability of heads is 50 %.