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Hypothesis Testing & Confidence Interval for Mean

Children's scores on a measure of aggression are known to have a normal distribution, with a mean of 50 and a standard deviation of 6. A researcher takes a random sample of 49 children, has them listen to calming music for 4 hours, and then measures the aggression level of this sample of children. The sample has a mean of 51. Using a directional hypothesis with a=0.5, complete the following items:

State the null hypothesis in statistical terms, using statistical notation.

Stae the alternative hypothesis in statistical terms.

Define the critical region by drawing the distribution and labeling the z-critical value.

Compute the test statistic. z =

What is your decision regarding the null hypothesis?

Copmpute effect size, if appropriate.

Write a sentence in APA style regarding the results of this study. Include your test statistic (z) written in journal form, as well as any other pertinent statistics.

Construct 90% confidence interval for the population mean of children's aggression after listening to music, wheather it is appropriate or not.

Interpret your confidence level, that is, report the results of your esitmation in a sentence.

Solution Summary

The solution provides step by step method for the calculation of testing of hypothesis and confidence interval for population mean. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.