Continuing the last question what is the variance of X a 253 b 10 c 25 d 100 e

Continuing the last question what is the variance of

This preview shows page 4 - 5 out of 5 pages.

16. Continuing the last question, what is the variance ofX? (a) 25/3(b) 10(c) 25(d) 100(e) none of the above 17. LetZbe a standard normal random variable, Φ the standard normal cdf, andcan arbitrarypositive number. Which of the following expressions isfalse? (Hint: draw a picture.) 18. LetZbe a standard normal random variable, Φ the standard normal cdf, andcan arbitrarypositive number. Which of the following quantities is larger than the others? 4
Background image
19. LetXbe a normal random variable with mean 85 and standard deviation 10. Knowing thatΦ(1.5) = 0.9332, what is the probability thatX70? 20. LetXbe the time (hours) between two successive arrivals at the drive-up window of a localbank. SupposeXfollows an exponential distribution withλ= 1; so the cdf ofXis given byF(x) =(0x <01-e-xx0Given that the last arrival occurred half an hour ago, what is the probability that no one elsewill arrive within the next half hour? (a)e-1(b) 1-e-1(c)e-1/2(d) 1-e-1/2(e) none of the above 5
Background image

You've reached the end of your free preview.

Want to read all 5 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture