Suppose a system contains a component whose length is normally distributed with a mean of 2.0 and a standard deviation of 0.2. If 5 of these components are removed from different systems, what is the probability that at least 2 have a length smaller than 2.1?

The distribution of lengths of salmon from a certain river is approximately normal with standard deviation 3.5 inches. If 10 percent of salmon are longer than 30 inches, which of the following is closest to the mean of the distribution? 26 inches 28 inches 30 inches 33 inches E 34 inches

letX1 and X2 be two independent normal random variables with means 5 (ofX1) and 5.5(of X2), respectively and with the same standard deviation 1.5 suppose X1 and X2 represent, the time (in months) needed to construct two different electronic devices. which is the distribution of X1-X2? compute the probability that the time needed to construct the second device (X2) is less than the one needed to construct the first device (X1).

The defect length of a corrosion defect in a pressurizedsteel pipe is normally distributed with mean value 30 mmand standard deviation 7.8 mm [suggested in the article“Reliability Evaluation of Corroding PipelinesConsidering Multiple Failure Modes and TimeDependent Internal Pressure” (J. of InfrastructureSystems, 2011: 216–224)].a. What is the probability that defect length is at most20 mm? Less than 20 mm?b. What is the 75th percentile of the defect length dis-tribution—that is, the value that separates the small-est 75% of all lengths from the largest 25%?c. What is the 15th percentile of the defect lengthdistribution?d. What values separate the middle 80% of the defectlength distribution from the smallest 10% and thelargest 10%?

Suppose that the antenna lengths of woodlice are approximately normally distributed with a mean of 0.22 inches and a standard deviation of 0.05 inches. What proportion of woodlice have antenna lengths that are at least 0.23 inches? Round your answer to at least four decimal places.

Suppose that, on average, electricians earn approximately µ = $54,000 per year in the United States. Assume that the distribution for electricians’ yearly earnings is normally distributed and that the standard deviation is σ = $12,000. What is the probability that the average salary of four randomly selected electricians exceeds $60,000?Multiple Choice0.15870.69150.30850.8413