When answering a question on multiple choice test with 4 answeres, a student either knows the answer or he guesses. the probability that he knows the answer is 0.80. what is the probability that a student knew the answer to a question given that he answered it correctly?

0.9412

Explanation:

Let's assume that there are 4 choices to each question and 1 of them is correct.

Hence, probability of answering a question correctly = P(A) =\frac{1}{4} = 0.25

Probability of students who knows the answer = P(B) =0.80

Hence, Probability of students who guesses the answer = P(B^c) =1-0.80 = 0.20

We need to find out probability that a student knew the answer to a question given that he answered it correctly i.e. P(B|A)

As per Baye's Theorem, P(B|A) =\frac{P(B)P(A|B)}{P(B)P(A|B)+P(A|B^c) P(B^c)}

P(A|B) = Probability of answering a question correctly given that the student knows the answer = 1

Hence, P(B|A) =\frac{0.80 \times 1}{0.80 \times 1+0.25 \times 0.20} = 0.9412

muslims have taken his goods and products to different parts of asia an indonesia. sometimes just traveled and trade, but in other occasions, stayed in the place and made a living.

trade was the key for muslims economies to prosper. their commerce routes reached far places like malaysia and java in the 11th century.

another important factor for prosperity was that muslim states served as the middle point for european traders.

they used to travel by land but sailing the seas -the indian ocean- really increase the exportation of products.

d.

thist title points out that you are explaining the nature of the u.s. government. it is the most specific. a representative government consists of a government where decisions are taken according to a voting system. the most essential aspect of a representative government is found in the different structures where voting rights are granted to different groups of people. for example, voting for governor, mayor, president, local police chief etc.