1) Survey showed 75 new employees hired at one employment place had an average salary of $60K with standard deviation of $20K. At another employment place, the average income of 60 households surveyed showed $85K with standard deviation of $25K. At significance level of 0.05, can a surveyor conclude that population means are different?
2) A random sample of 20 observations from the first population revealed a sample mean of 325 and a sample standard deviation of 15. A random sample of 25 observations from the second population revealed a sample mean of 316 and a sample standard deviation of 20. At the 0.10 significance level, is there a difference in the population mean?
The solution provides step by step method for the calculation of test statistic for independent sample t test . 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.