Reference no: EM13532202

1. a computer manufacturer offers a help line that purchasers can call for help 24 hours a day 7 days a week. Clearing these calls for help in a timely fashion is important to the company's image. After telling the caller that resolution of the problem is important, the caller is asked whether the issue is software or hardware related. The mean time it takes a technician to resolve a software issue is 18 minutes with a standard deviation of 4.2 minutes. This information was obtained from a sample of 35 monitored calls. For a study of 45 hardware issues, the mean time for the technician to resolve the problem was 15.5 minutes with a standard deviation of 3.9 minutes. This information was also obtained from monitored calls. At the .05 significance level, does it take longer to resole software issues?
A. write the null and alternative hypothesis?
B. significance level? .05
C. solve for z?
D. write the decision rule?
E. Accept or Reject? why?

2. There are two major Internet providers in the Colorado Springs, Colorado, area, one called HTC and the other Mountain Communications. We want to investigate whether thee is a difference in the proportion of times a customer is able to access the internet. During a one-week period, 500 calls were placed at random times throughout the day and night to HTC. A connection was made to the internet on 450 occasions. A similar one-week study with Mountain Communications showed the internet available on 352 of 400 trials. At the .01 significance level, is there a difference in the percent of time that access to the internet is successful?
A. write the null and alternative hypothesis?
B. significance level? .01
C. solve for z?
D. write the decision rule?
E. Accept or Reject? why?

3. Dole Pineapple Inc. is concerned that the 1-ounce can of sliced pineapple is being overfilled. Assume the standard deviation of the process is .03 ounces. The quality-control department took a random sample of 50 cans and found that the arithmetic mean weight was 16.05 ounces. At the 5% level of significance, can we conclude that the mean weight is greater than 16 ounces?
A. write the null and alternative hypothesis? Ho: u = 16 ; H1: u > 16
B. significance level? .05
C. solve for z?
D. write the decision rule?
E. Accept or Reject? why?

4. For a recent year, the mean fare to fly from Charlotte, North Carolina, to Seattle, Washington, on a discount ticket was $267. A random sample of round-trip discount fares on the route last month gives: ( $321 $286 $290 $330 $310 $250 $270 $280 $299 $265 $291 $275 $281). At the .0 significance level, can we conclude that the mean fare has increased?
A. write the null and alternative hypothesis?
B. significance level? .01
C. solve for z?
D. write the decision rule?
E. Accept or Reject? why?