1) Computer manufacturer offers help line that purchasers can call for help 24 hours a day 7 days a week. Clearing these calls for help in timely fashion is significant to company's image. After telling caller that resolution of problem is significant the caller is asked whether issue is "software" or "hardware" related. Mean time it takes technician to resolve software issue is 18 minutes with standard deviation of 4.2 minutes. This information was attained from sample of 35 monitored calls. For study of 45 hardware issues, mean time for technician to resolve the problem was 15.5 minutes with standard deviation of 3.9 minutes. This information was also attained from monitored calls. At.05 significance level is it reasonable to conclude that it takes longer to determination software issues? Determine the p-value?
Q2) Liquid chlorine added to swimming pools to combat algae has relatively short shelf life before it loses its effectiveness. Records point out that mean shelf life of 5-gallon jug of chlorine is 2,160 hours (90 days). As the experiment, Holdlonger was added to chlorine to determine whether it would rise the shelf life. A sample of nine jugs of chlorine had these shelf lives (in hours):
|
2,159
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2,170
|
2,180
|
2,179
|
2,160
|
2,167
|
2,171
|
2,181
|
2,185
|
At.025 level, has Holdlonger increased shelf life of chlorine? Evaluate the p-value.