99 percent confidence. (Round your answers to 4 decimal places.)
Population standard deviation
99 percent confidence interval:
The z-critical value at
Margin of error:
The margin of error is calculated as given below:
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:
In a science fair project, Emily conducted an experiment in which she tested professional touch therapists to see if they could sense her energy field. She flipped a coin to select either her right hand or her left hand, and then she asked the therapists to identify the selected hand by placing their hand just under Emily's hand without seeing it and without touching it. Among 358 trials, the touch therapists were correct 172 times. Complete parts (a) through (d).
a) Given that Emily used a coin toss to select either her right hand or her left hand, what proportion of correct responses would be expected if the touch therapists made random guesses? (Type an integer or a decimal. Do not round.)
b) Using Emily's sample results, what is the best point estimate of the therapists' success rate? (Round to three decimal places as needed.)
c) Using Emily's sample results, construct a
Round to three decimal places as needed - ?