Portage Learning Math 110 Module Exam 4
1. In a large shipment of clocks, it has been discovered that 21 % of the clocks are
defective. Suppose that you choose 7 clocks at random. What is the probability that 2 or
less of the clocks are defective.
2. Find each of the following probabilities: (use standard normal distribution table to get z-
score)
a.Find P(Z ≤ 1.27) .
b.Find P(Z ≥ -.73) .
c. Find P(-.09 ≤ Z ≤ .86).
a. P(Z ≤ 1.27) =0.89796
b.P(Z ≥ -0.73= 1- P(Z ≤ -0.73)=1-
0.23270=0.7673
c. P(-0.09 ≤ Z ≤0 .86)= P(Z≤0 .86)- P(Z≤ -0.09) 0.80511-
0.46414=.34097
1. In a large shipment of clocks, it has been discovered that 21 % of the clocks are
defective. Suppose that you choose 7 clocks at random. What is the probability that 2 or
less of the clocks are defective.
2. Find each of the following probabilities: (use standard normal distribution table to get z-
score)
a.Find P(Z ≤ 1.27) .
b.Find P(Z ≥ -.73) .
c. Find P(-.09 ≤ Z ≤ .86).
a. P(Z ≤ 1.27) =0.89796
b.P(Z ≥ -0.73= 1- P(Z ≤ -0.73)=1-
0.23270=0.7673
c. P(-0.09 ≤ Z ≤0 .86)= P(Z≤0 .86)- P(Z≤ -0.09) 0.80511-
0.46414=.34097
