Use the rule of total probability to find the indicated probability.
-A teacher designs a test so a student who studies will pass 82% of the time, but a student who does not study will pass 13% of the time. A certain student studies for 81% of the tests taken. On a given
Test, what is the probability that student passes?
A)0.664
B)0.247
C)0.689
D)0.475

Question

Use the rule of total probability to find the indicated probability.
-A teacher designs a test so a student who studies will pass 82% of the time, but a student who does not study will pass 13% of the time. A certain student studies for 81% of the tests taken. On a given
Test, what is the probability that student passes? 
A)0.664
B)0.247
C)0.689
D)0.475

Quizplus · Accepted Answer

The probability that the student passes is calculated using the rule of total probability: P(Pass) = P(Pass|Study)P(Study) + P(Pass|Not Study)P(Not Study) = 0.82 * 0.81 + 0.13 * 0.19 = 0.689.

Use the Rule of Total Probability to Find the Indicated