Discussion:
Confidence interval for the population mean: Use of the t distribution.
Q: 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.
What is the lower limit of the confidence level?
What is the upper limit of the confidence level?