HW5: Ch 7 Instructions I help Question 13 (of 15 Save & Exit Submit 6.66 points

Question

HW5: Ch 7 Instructions I help Question 13 (of 15 Save & Exit Submit 6.66 points Passengers using New York's MetroCard system must swipe the card at a rate between 15 and 32 inches per second, or else the card must be re-swiped through the card reader. Research shows that actual swipe rates by subway riders are uniformly distributed between 5 and 41 inches per second. (a) What is the mean swipe rate? (Round your answer to 2 decimal places.) Mean per second (b) What is the standard deviation of the swipe rate? (Round your answer to 2 decimal places.) Standard deviation inches per second (c) What are the quartiles? (Round your answers to 2 decimal places.) 1st Quartile 3rd Quartile inches per second inches per second (d) What percentage of subway riders must re-swipe the card because they were outside the acceptable range? (Round your answer to 2 decimal places.) Re-swipe References eBook & Resources

Explanation / Answer

Here, base = 41 -5 = 36
width = 1/36

a) mean swipe rate = ( 41 +5) / 2 = 23 inches per second

b) Std . deviation = sqrt[( 5 - 41)^2/12]
= 10.3923 inches per second

c) 1st quartile
Point with left tail = 0.25
base(1/36) = 0.25
base = 36*0.25
base = 9
But base starts at 5 so the 1st quartile value is 5 + 9 = 14 inches per second

third quartile
Point with left tail of 0.75
base(1/36) = 0.75
base = 36*0.75
base = 27
But base starts at 5 so the 3rd quartile value is 5 + 27 = 32 inches per second

d) p(15 < x < 32) = ( 1/ ( 5 - 41))* ( 32 -15) = -0.4722
Reswipe = 1- P(15 < x < 32)
= 1 - ( -0.4722)
= 1.4722 = 147.22%

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

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