A random variable is said to have probability density function
if and only if
and the probability of that is
This gives you a confidence interval for k if is known. Since is not known, there is more work to do. (You have to choose A and B to get you the probablities that you want.)
A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before treatment, 13 subjects had a mean wake time of 101.0 min. After treatment, the 13 subjects had a mean wake time of 94.6 min and a standard deviation of 24.9 min. Assume that the 13 sample values appear to be from a normally distributed population and construct a
What does the result suggest about the mean wake time of 101.0 min before the treatment? Does the drug appear to be effective?
The confidence interval ▼ does not include| includes the mean wake time of 101.0 min before the treatment, so the means before and after the treatment ▼ could be the same |are different. This result suggests that the drug treatment ▼ does not have | has a significant effect.
In a study of the accuracy of fast food drive-through orders, Restaurant A had 298 accurate orders and 51 that were not accurate. a. Construct a 90% confidence interval estimate of the percentage of orders that are not accurate. b. Compare the results from part (a) to this 90% confidence interval for the percentage of orders that are not accurate at Restaurant B:
Consider a random sample of size n = 31, with sample mean