50 components are placed on a life test. The recorded times to failure, in hours, are saved in "Ex3_8.csv". The sample data suspected of coming from a population of lifetimes that can be adequately modeled by an exponential distribution. Analyze the sample data as follows:

a. Construct a histogram using cell intervals of size 500 (from 0 to 5000).

b. Estimate and the MTTF using the exact failure times.

c. Estimate the median time to fail using the estimated in (b).

d. Test the adequateness of the exponential model using the chisquare goodnessoffit test and a

confidence (or significance) level of 90%. Use the same intervals as in part a, combining

everything greater than 2000 hours into one group.

e. Suppose the test had been planned to stop upon the fifth failure and hence ended at 112 hours.

What would the estimated MTTF be for this experiment? Suppose instead the test had been

planned to stop at 150 hours. What MTTF estimate would have resulted?

f. Compute the upper 90% upper bound for for the complete data as well as the two cases of

censored data in (e).