Science & Mathematics - 29 August 2007

Thanks :)

1. The joint density for x and y is given by f(x,y) = 1/n2, x = 1, 2, 3, ..n, y = 1, 2, 3, ..n where n is a positive integer
a. Verify that f(x,y) satisfies the conditions necessary to be a density
b. Find the marginal densities for x & y
c. Are x & y independent?

3. Let X denote the temperature (oC) and let Y the time in minutes that it take for the diesel engine on an automobile to get ready to start. Assume that the joint density for x & y is given by f(x,y) = c(4x+2y+1), 0 ≤ x ≤ 40, 0 ≤ y ≤ 2
a. Find the value of c
b. Find the probability that on a randomly selected day, the air temperature will exceed 20oC and it will take at least 1 minute for the car to be ready to start
c. Find the marginal densities for x & y
d. Are x & y independent?
e. Find the probability that in a randomly selected day it will take at least 1 minute for the car to be ready to start

Thanks again! :)

2007-08-29 02:28:21 · 1 answers · asked by infinitelimits 2 in Mathematics

this is the problem:

Simply |-32|

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Thanks

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3V108-3V32

The V's are the square root symbols and the 3's are actually small subscripts representing the 3rd root.

Please help!

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