Question

A study shows that 35% of the fish caught in a local lake had high levels of mercury. Suppose that 10 fish were caught from this lake. Find, to the nearest tenth of a percent, the probability that at least 6 of the 10 fish caught did not contain high levels of mercury.

Answer 1

0.985

Explanation:

Given: 35% of the fish caught in a local lake had high levels of mercury.

To find: probability that at least 6 of the 10 fish caught did not contain high levels of mercury

Solution:

Probability refers to chances of occurrence of some event.

Probability = number of favourable outcomes/Total number of outcomes

Let A denotes the event that the fish caught in a local lake had high levels of mercury.

As 35% of the fish caught in a local lake had high levels of mercury,

`P(A)=0.35`

Probability that at least 6 of the 10 fish caught did not contain high levels of mercury = 1 - probability that 4 of the 10 fish caught contain high levels of mercury =
`1-(0.35)^4=1-0.015=0.985`