Question

It is known that 10% of adults can pass a fitness test. What notation would be used to describe a count of the number of adults who pass this fitness test when 50 adults are sampled?
A. x ~ B(.01, 50)
B. x ~ B(50, .1)
C. x ~ B(50, .01)
D. x ~ B(.1, 50)

Answer 1

Answer:  B. x ~ B(50, .1)

In other words, it's the second answer choice

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Explanation:

We have n = 50 people in the sample and p = 0.10 is the decimal form of 10%, to represent the probability of success. In this case, we define "success" as "the person passes the fitness test".

The random variable x is the count of how many people pass. So we could have x = 0, x = 1, x = 2, ..., x = 49, x = 50. Basically any whole number from 0 to 50 inclusive. Furthermore, x is approximately modeled by the binomial distribution which we denote as B(n, p) = B(50, 0.1)

So X ~ B(50, 0.1)