Answer:
0.8594
Step-by-step explanation:
Let a denote the event of forgetting to shut off machine and b be the event of being defective.
-A foreman forgets to shut off machine 55% of the time.
-If he forgets, 15% of molds are defective.
-If he does not, 3% of molds are defective.
#The probability that he forgot to shut off the machine is calculated as:
P(a and ~b)=0.55(1-0.15)=0.4675
P(~a and b) = (1-0.55)*0.03=0.0135
P(~a and ~b) = (1-0.55)*(1-0.03)=0.4365
#Conditional probability is defined as:
Hence, the probability that the foreman forgot to shut off the machine the previous night is 0.8594