Questions from Engineering Statistics

Q: Refer to Exercise 9.22. Why are the quantities requested

Refer to Exercise 9.22. Why are the quantities requested in the exercise likely to be more important to the manufacturer of the thread than, say, a confidence interval on the mean tensile strength?...

Q: For a chi-squared distribution, find χ2 α such that

For a chi-squared distribution, find χ2 α such that (a) P(X2 > χ2α) = 0.99 when v = 4; (b) P(X2 > χ2α) = 0.025 when v = 19; (c) P(37.652 < X2 < χ2α) = 0.045 when v = 25.

Q: The number of tickets issued for traffic violations by 8 state troopers

The number of tickets issued for traffic violations by 8 state troopers during the Memorial Day weekend are 5, 4, 7, 7, 6, 3, 8, and 6. (a) If these values represent the number of tickets issued by a...

Q: For a chi-squared distribution, find χ2α such that

For a chi-squared distribution, find χ2α such that (a) P(X2 > χ2α) = 0.01 when v = 21; (b) P(X2 < χ2α) = 0.95 when v = 6; (c) P(χ2α < X2 < 23.209) = 0.015 when v = 10.

Q: Assume the sample variances to be continuous measurements. Find the probability

Assume the sample variances to be continuous measurements. Find the probability that a random sample of 25 observations, from a normal population with variance σ2 = 6, will have a sample variance S2 (...

Q: The scores on a placement test given to college freshmen for the

The scores on a placement test given to college freshmen for the past five years are approximately normally distributed with a mean μ = 74 and a variance σ2 = 8. Would you still consider σ2 = 8 to be...

Q: Show that the variance of S2 for random samples of size n

Show that the variance of S2 for random samples of size n from a normal population decreases as n becomes large.

Q: (a) Find t0.025 when v = 14.

(a) Find t0.025 when v = 14. (b) Find −t0.10 when v = 10. (c) Find t0.995 when v = 7.

Q: (a) Find P(T < 2.365)

(a) Find P(T < 2.365) when v = 7. (b) Find P(T > 1.318) when v = 24. (c) Find P(−1.356 < T < 2.179) when v = 12. (d) Find P(T > −2.567) when v = 17.

Q: (a) Find P(−t0.005 < T <

(a) Find P(−t0.005 < T < t0.01) for v = 20. (b) Find P(T > −t0.025).