Confidence interval for the population mean: Use of the t distribution.
A toy manufacturer wants to see how long, on average, a new toy captures children's attention. He tests 10 children selected at random and finds that their mean attention span is 33 minutes with a standard deviation of 6 minutes. If we assume that attention spans are normally distributed, find a 90% confidence interval for the mean attention span of children playing with this new toy. Then complete the table below.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
What is the lower limit of the confidence level? ________________
What is the upper limit of the confidence level? ________________
This solution provides a step by step method for the calculation of confidence interval limits for the population mean attention span of children. Formula for the calculations and interpretations of the results are also included. The solution is provided in a Word document and all the calculations can be understood by viewing the attached Excel document.