We have two methods a and b available for teaching a certain industrial skill. there is a 75% chance of successfully learning the skill if method a is used, and a 95% chance of success if method b is used. however, method b is substantially more expensive and is therefore used only 20% of the time(method a is used the other 80% of the time) a worker learned the skill successfully.

what is the probability that he was taught by method a?

75.95% probability that he was taught by method A.

Step-by-step explanation:

We have these following probabilities:

An 80% probability of method A being used.

A 20% probability of method B being used.

If method A is used, a 75% probability of learning the skill successfully.

If method B is used, a 95% probability of learning the skill successfully.

This exercise can be formulated as the following problem:

What is the probability of B happening, knowing that A has happened.

It can be calculated by the following formula

Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.

So

What is the probability of him being taught by method A, given that he learned the skill succesfully.

P(B) is the probability of being taught by method A, so P(B) = 0.80.

P(A/B) is the probability of learning the skill successfully, given that he was taught by method A. So P(A/B) = 0.75.

P(A) is the probability of learning the skill successfully. It is 75% of 80% plus 95% of 20%. So

Finally

There is a 75.95% probability that he was taught by method A.

a line is an defined derm because it

a)contains an infinite number of points b) can be used to create other geometric shapes c)describes something that does not have width or depth d) is a term that does not have a formal definition. a line is an undefined term because it: contains an infinite number of points.