An experiment measuring American adults' reaction time to a visual response resulted in a random sample of 40 trials with a mean of 304.3 milliseconds. You may assume the population standard deviation is 78.0 milliseconds. Use this information to answer questions 17 and 18. 17. Construct a 99% confidence interval for the mean reaction time for all American adults. 18. Would the interval become in question 17 wider or narrower if the level of confidence were changed to 90%?

An existing inventory for a test measuring self-esteem indicates that the scores have a standard deviation of 8. A psychologist gave the self-esteem test to a random sample of 70 individuals, and their mean score was 69. Construct a 99% confidence interval for the true mean of all test scores. 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  99%  confidence interval?   What is the upper limit of the  99%  confidence interval?

Please help with question 5 a-b

In a survey, 10 people were randomly chosen and asked how much they spent on their auto insurance per year. The results were roughly bell-shaped with a mean of $920 and standard deviation of $107. Find a 99% confidence interval for the true population mean amount of money that typical drivers would spend on their auto insurances. Always write the final answer as a complete sentence. Give your answers rounded to two decimal places. ANSWER: It can be stated with 99% confidence that the true population mean amount of money that people spend on their auto insurance lies in the interval dollars per year Question Help: M Message instructor