Suppose the duration of trouble-free operation of a new robotic vacuum cleaner is normally distributed with mean 740 days and standard deviation 100 days.

(a) What is the probability that a new vacuum cleaner with be trouble-free for at least two years?
Sketch the normal distribution and shade the area of interest for the standard normal distribution.

(b) The manufacturer wishes to set the warranty period so that no more than 5 % of the robotic vacuum cleaners would require repair services while under warranty. Determine the warranty period.

Question

Suppose the duration of trouble-free operation of a new robotic vacuum cleaner is normally distributed with mean 740 days and standard deviation 100 days.

(a) What is the probability that a new vacuum cleaner with be trouble-free for at least two years?
Sketch the normal distribution and shade the area of interest for the standard normal distribution.

(b) The manufacturer wishes to set the warranty period so that no more than 5 % of the robotic vacuum cleaners would require repair services while under warranty. Determine the warranty period.

Quizplus · Accepted Answer

The Answer of  Suppose the duration of trouble-free operation of a new robotic vacuum cleaner is normally distributed with mean 740 days and standard deviation 100 days.

(a) What is the probability that a new vacuum cleaner with be trouble-free for at least two years?
Sketch the normal distribution and shade the area of interest for the standard normal distribution.

(b) The manufacturer wishes to set the warranty period so that no more than 5 % of the robotic vacuum cleaners would require repair services while under warranty. Determine the warranty period.

Suppose the Duration of Trouble-Free Operation of a New Robotic