There are 5 white balls, 8 red balls, 7 yellow balls and 4 green balls in a container. A ball is chosen at random.
What is the probability of choosing red?
The total number of balls in the container is 5 + 8 + 7 + 4 = <<5+8+7+4=24>>24.
The probability of choosing a red ball is 8/24 = <<8/24=0.3333333333333333>>0.33 or 33.33%. Answer: \boxed{0.33}.