Probability and Statistics: The control department of a light bulb manufacturer randomly picks 4400 light bulbs from the production lot every week. The records show that, when there is no malfunction, the defect rate in the manufacturing process (due to imperfections in the material used) is 1% . When 1.5% or more of the light bulbs in the sample of 4400 are defective, the control unit calls repair technicians for service.

Question

anonymous · Answer

Compute an approximation for P (p≥0.015), which is the probability that the service technicians will be called even though the system is functioning properly. Round your answer to four decimal places.

anonymous · Answer

std = 0.015/sqrt(4400) = 0.0002261

z(0.015) = (0.015-0.01)/0.0002261 = 22.1141

So I got P (z ≥ 22.11) ... but I don't know where to go from there

anonymous · Answer

can I use normalcdf to figure it out?