<PRE><B>Question 193171</B>
In a ten-question multiple-choice test with four choices for each question, a student who was not prepared guesses on each item. Find each probability.
P(correct) = 1/4 ; P(wrong) = 3/4
--------------------------------------------
a. P(six questions correct)= 10C6*(1/4)^6*(3/4)^4 = 0.01622
-------------------------------------------------
b. P(at least eight questions are correct)= 1-binomcdf(10,1/4,7) = 0.000415802...
-------------------------------------------------
c. P(fewer than eight questions correct) binomcdf(10,1/4,7) = 0.99958
========================================================================
Cheers,
Stan H.
</PRE>