authors studied the impact of several factors involving the heat treatment of le
ID: 3363720 • Letter: A
Question
authors studied the impact of several factors involving the heat treatment of leaf springs. In this process, a conveyor system transports leaf spring assemblies through a high temperature furnace. After the spring leaves a high pressure press, an oil quench cools it to near room temperature . An important material property of this process is the resulting free height of the spring, which should ideally be 8 inches. A materials engineer assigned to this process believes that the heating time affects this free height and so carries out 25 tests at two different times - 23 seconds and 25 seconds. The results are shown here: Spring free height at:23 seconds 25 seconds 7.12 7.33 7.33 7.54 7.34 7.77 7.37 8.07 7.45 8.1 7.47 8.14 7.51 8.23 7.51 8.26 7.52 8.27 7.53 8.31 7.56. 8.31 7.57 8.36 7.57 8.36 7.61 8.36 7.65 8.37 7.66 8.37 7.67 8.39 7.67 8.42 7.67 8.42 7.67 8.45 7.71 8.45 7.71 8.46 7.71 8.48 7.71 8.49 7.75 8.53 23 seconds 25 seconds 7.12 7.33 7.33 7.54 7.34 7.77 7.37 8.07 7.45 8.1 7.47 8.14 7.51 8.23 7.51 8.26 7.52 8.27 7.53 8.31 7.56. 8.31 7.57 8.36 7.57 8.36 7.61 8.36 7.65 8.37 7.66 8.37 7.67 8.39 7.67 8.42 7.67 8.42 7.67 8.45 7.71 8.45 7.71 8.46 7.71 8.48 7.71 8.49 7.75 8.53
QUESTION 7 Assuming the spring free height data obtained at 25 seconds has a normal distribution, what is the least squares estimator for the population parameter when the median method is used to compute the empirical cd. Provide your answer to 3 decimal places. QUESTION8 Calculate 75% confidence intervals for the mean spring free height at 23 and 25 seconds, assuming the responses are normally distributed. Which of the following statements is a correct interpretation of these intervals: It can be concluded, with only a 25% chance of being wrong, that the population mean spring free height is the same for each time as and 25 seconds) It can be concluded, with only a 25% chance of being wrong, that the population mean spring free height is different for each time(23 and 25 seconds). O It can be concluded, with only a 25% chance of being wrong, that the sample mean spring free height is different for each time (23 and 25 C) It can be concluded with only a 25% chance of being wrong, that the sample mean spring free height is the same for each time(23 and 25 None of the options given. seconds) seconds)
Explanation / Answer
7) To calculate median of the sample elements Ti, we order the sample elements Ti in increasing order of magnitude T(1), T(2), … ,T(s+1) , ... , T(r), where r=2s+1 and take the middle value T(s+1) of this sequence as the median estimator of
for 25 seconds data, the median lse is 8.36
8) option C
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.