The standard deviation of test scores on a certain achievement test is 11.4. A random sample of 100 scores on this test had a mean of 71.2. Based on this sample, find a 90% confidence interval for the true mean of all scores. Complete the below:
What is the lower limit of the 90% confidence interval:___
What is the upper limit of the 90% confidence interval:___
The solution provides step by step method for the calculation of confidence interval for mean . Formula for the calculation and Interpretations of the results are also included.