Questions from Engineering Statistics

Q: Computer response time is an important application of the gamma and exponential

Computer response time is an important application of the gamma and exponential distributions. Suppose that a study of a certain computer system reveals that the response time, in seconds, has an expo...

Q: Consider the data displayed in Exercise 1.20 on page 31

Consider the data displayed in Exercise 1.20 on page 31. Construct a box-and-whisker plot and comment on the nature of the sample. Compute the sample mean and sample standard deviation.

Q: Consider the drying time measurements in Exercise 9.14. Suppose

Consider the drying time measurements in Exercise 9.14. Suppose the 15 observations in the data set are supplemented by a 16th value of 6.9 hours. In the context of the original 15 observations, is th...

Q: If X1,X2, . . . , Xn are independent

If X1,X2, . . . , Xn are independent random variables having identical exponential distributions with parameter θ, show that the density function of the random variable Y = X1+X2+· · ·+Xn is that of a...

Q: In testing for carbon monoxide in a certain brand of cigarette,

In testing for carbon monoxide in a certain brand of cigarette, the data, in milligrams per cigarette, were coded by subtracting 12 from each observation. Use the results of Exercise 8.14 on page 231...

Q: If S21 and S22 represent the variances of independent random samples of

If S21 and S22 represent the variances of independent random samples of size n1 = 8 and n2 = 12, taken from normal populations with equal variances, find P(S21/S22 < 4.89).

Q: Find the mean, median, and mode for the sample whose

Find the mean, median, and mode for the sample whose observations, 15, 7, 8, 95, 19, 12, 8, 22, and 14, represent the number of sick days claimed on 9 federal income tax returns. Which value appears t...

Q: A random sample of 5 bank presidents indicated annual salaries of $

A random sample of 5 bank presidents indicated annual salaries of $395,000, $521,000, $483,000, $479,000, and $510,000. Find the variance of this set.

Q: If the number of hurricanes that hit a certain area of the

If the number of hurricanes that hit a certain area of the eastern United States per year is a random variable having a Poisson distribution with μ = 6, find the probability that this area will be hit...

Q: A taxi company tests a random sample of 10 steel-belted

A taxi company tests a random sample of 10 steel-belted radial tires of a certain brand and records the following tread wear: 48,000, 53,000, 45,000, 61,000, 59,000, 56,000, 63,000, 49,000, 53,000, an...