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Significance, Hypothesis Test

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1. In research, one often hopes to be able to state results using a confidence level that the results are valid of 90% or more. To test results to determine the confidence level, what is the significance of locating the test statistic in the tail that has a probability less than ά, which implies a confidence level of 1-(alpha)?

2. In a hypothesis test, one establishes the hypothesis that one hopes to be proved. The hypothesis is proved if the null hypothesis is disproved. To disprove the null hypothesis, one must show, with a degree of confidence, that the chance for the alpha error is less than ά, in which the confidence level is 1 - (the alpha percentage). What is the alpha error in a hypothesis test? What is the Beta error in the hypothesis test?

3. In inferential statistics, it is important, if it is unknown whether the probability distribution of the universe is a normal distribution, to use a sample size that allows the use of the central limit therom. In analysis, the assumption of a normal distribution lets one use the mean of the sample distribution to determine what about the probability distribution of the universe?

4. What are the assumptions necessary to use the z-series test? What are the assumptions necessary o use the t-series test?

Lind, Marchal, and Wathen, (2005) Statistical Techniques in Business & Economics

Please indicate other references and information from Linds, Marchal, and Wathen. Also provide examples if you can.

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Solution Summary

The solution examines significance and hypothesis tests.

Solution provided by:
Changping Wang, MA
Education
  • BSc , Wuhan Univ. China
  • MA, Shandong Univ.
Recent Feedback
  • "Your solution, looks excellent. I recognize things from previous chapters. I have seen the standard deviation formula you used to get 5.154. I do understand the Central Limit Theorem needs the sample size (n) to be greater than 30, we have 100. I do understand the sample mean(s) of the population will follow a normal distribution, and that CLT states the sample mean of population is the population (mean), we have 143.74. But when and WHY do we use the standard deviation formula where you got 5.154. WHEN & Why use standard deviation of the sample mean. I don't understand, why don't we simply use the "100" I understand that standard deviation is the square root of variance. I do understand that the variance is the square of the differences of each sample data value minus the mean. But somehow, why not use 100, why use standard deviation of sample mean? Please help explain."
  • "excellent work"
  • "Thank you so much for all of your help!!! I will be posting another assignment. Please let me know (once posted), if the credits I'm offering is enough or you ! Thanks again!"
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