A random sample is used to estimate the mean time required for caffeine from pro

Question

A random sample is used to estimate the mean time required for caffeine from products such as coffee or soft drinks to leave the body after consumption. A 95% confidence interval based on this sample is: 5.6 hours to 6.4 hours (for adults). What is the sample mean (X)? A random sample is used to estimate the mean time required for caffeine from products such as coffee or soft drinks to leave the body after consumption. A 95% confidence interval based on this sample is: 5.6 hours to 6.4 hours (for adults). What is the margin of error? How many commuters must be randomly selected to estimate the mean driving time of Chicago commuters? We want 95% confidence that the sample mean is within 3 minutes of the population mean, and the population standard deviation is known to be 12 minutes. 62 commuters 61 commuters 7 commuters 8 commuters If we increase our sample size the width of the confidence interval will increase

Explanation / Answer

Q3)

Sample mean = Average of upper bound and lower bound of confidence interval = (5.6+6.4)/2 = 6.0

Q4) Similarly, doing an extra question 4, margin of error =( Upper bound - lower bound )/2 =( 6.4-5.6)/2 = 0.4

Q5) 3 = 1.96* 12/sqrt(n) which gives n as 61.56. We take the higher value, so n = 62 commuters

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.