In: Statistics and Probability
1. Let X have a normal distribution with parameters μ = 50 and
σ2 =
144. Find the probability that X produces a value between 44 and
62. Use the
normal table A7 (be sure to show your work).
2. Let X ~ Exponential( λ ), for some fixed constant λ > 0.
That is,
fX(x) = λ e-λx = λ exp( -λx ), x > 0, ( fX(x) = 0
otherwise)
(a) Create a transformed random variable Y = X1/3 (cube root of X).
Using
either the CDF method or Jacobian method, show that the
probability
density function of Y is given by: (10 pts)
fY(y) = 3λy^2e^(-λy3) , 0 < y < ∞.
(b) Verify that the CDF of Y is FY(y) = 1 - exp( -λy3 ), 0 < y
< ∞. (5 pts)
(Hint: Use the CDF from (a) or integrate the PDF answer in
(a)).
(c) If λ = 2, compute the median of Y (approximately). (5 pts)
i
if you are refering to the table above then the values are in the last row, ideally the table below should be the real standard normal table( biometrica format)