The weatherman predicted that today's temperature would be 64°F. It was actually 38°F. What was the percent error of the weatherman's prediction?
The percent error can be calculated using the formula:
Percent Error = (Observed Value - Expected Value) / Expected Value * 100
Therefore, the percent error in this case is:
(38 - 64) / 64 * 100 = -26 / 64 * 100 = -0.40625 * 100 = -40.625%
The percent error of the weatherman's prediction is approximately -40.625%.