A large disaster cleaning company estimates that 30 percent of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that it has contracted, find the probability that x (number of jobs finished on time) is within one standard deviation of the mean.
A) .6867
B) .2541
C) .5506
D) .8844

Question

Quizplus · Accepted Answer

μ_x = np = 8(0.3) = 2.4 σ === 1.3 2.4 ± 1.3 = (1.1, 3.7), which convert to (2, 3) for discrete probability P(2 < x < 3) = 0.2541

A Large Disaster Cleaning Company Estimates That 30 Percent of the Jobs