Assessment Questions On Statistics

Question:5

1. 99% confidence interval for mean breaking weight of executive desk is (48.5,55.18).
2. The means population value of breaking weights lies between (48.5,55.18) with 99% confidence level, the table should be launched in the market if the weight of the computer is less than the lower range of confidence interval.
3. 95% confidence level when population standard deviation is known.
4. The difference between the calculation of confidence interval in part a) and part c) is that in part a) population standard deviation was unknown so we calculated the sample standard deviation (s), on the other hand in part c) population standard deviation was known which is denoted with sigma. On the other hand, when population standard deviation is unknown, we use a t-test and when population standard deviation is known we use z-statistics.
   1. There will be two hypotheses, null hypothesis and alternative hypothesis. For the null hypothesis, we assume that the mean population breaking weight is equal to 0, and the alternative hypothesis will be that the mean population breaking weight is not equal to 0. we assume the same confidence level of 95% and will test the hypothesis by calculating z-statistics. So, if the p-value is less than 0.05 we will reject the null hypothesis that is mean population breaking weight is equal to 0. As per the results in c) zero does not lie in the confidence interval we will be able to reject the null hypothesis.