Aspinner is divided into 4 sections. the spinner is spun 100 times. the probability distribution shows the results.

what is p(1≤x≤3) ?

enter your answer, as a decimal.

P(1≤x≤3) defined the probability that the result is between 1 and 3, included. You can answer this question in two ways:

1. Sum the probabilities of good events:

From the graph, we have

So,

2. Use complementary probabilities

Asking that the result is 1, 2 or 3 is the same as asking that the result is not 4. The probability that the result is 4 is 0.16, so the probability that the result is not 4 will be

The result is obviously the same.

(a) the volume of the cone is 20/3 in3

hence, option a is correct.