Question

1. An overnight delivery service has a promotional discount rate in effect this week only. Twelve packages mailed this week were randomly selected to see if there is evidence that the mean weight of packages sent this week is higheir than usual. A 95% confidence interval for μ was found to be (10.64, 13.08), Using the context of the problem, give an interpretation of the interval. 2. In a survey about fears, 45 out of 250 randomly selected adults said that they were afraid of the dentist's chair Based on this sample data, a 95% confidence interval for the population proportion was found to be (0.136, 0.228). Using the context of the problem, give an interpretation of the confidence interval

Answer 1

1)

we are 95% confident that population mean weight of packages sent this week lies between bounds of interval 10.64 and 13.08.

2)

we are 95% confident that population proportion of people who are afraid of dentist's chair lies between bounds of interval 0.136 and 0.228