The function is the Sine Curve
y = sine (x)
Probability of getting the correct answer in the first question is 1/4
probability of getting the correct answer in the second question is 1/4
probability of getting the correct answer in the second question is 1/4 the probability that he gets one question wrong is 3/4
which is 1/4*1/4*1/4*3/4=3/256
for the four questions because he may get the first answer correct and my be the second question wrong, or the the third wrong and the other correct or the first wrong and others correct we should take care of all this by
multiplying 3/256*4=12/256
=0.046875
in three decimal places we have 0.047
Approximate solutions are
X subset 2 is approximately equal to -2.72
X subset 1 is approximately equal to -0.28
2.5 pounds of grain cost ======= $1.75
∴ 5.3 pounds of grain will cost ===== (5.3×1.75)/2.5 = $3.71
