1. Suppose that the error in the reaction temperature, in ◦C, for a controlled laboratory experiment is a continuous random variable X having the probability density function
f(x)=x2/3 for −1 <x<2,
f(x)=0, elsewhere
(a) Verify that f(x) is a density function
(b) Find P(0 <X≤ 1).
1
Expert's answer
2020-04-27T16:41:49-0400
"a)\\int_{-\\infty}^{\\infty}f(x)dx=1\\\\\n\\int_{-1}^{2}\\frac{2}{3}xdx=[\\frac{2}{3}\\frac{x^2}{2}]_{-1}^2=1.\\text{ So } f(x)\\text{ is pdf}."
Dear Kat, thank you for leaving a feedback. We found that cases 2x/3
and 1/3*x^2 meet conditions of the question. In other words, expert's
solution is not wrong.
Kat
24.02.21, 23:42
I think for part b of this problem, they meant to say (x²)/3, in
which case the answer to b is 1/9. Because the integral from 0 to 1 of
(x²)/3 is (x³)/9 from 0 to 1 which equals 1/9. At least that's how
my stats professor solved this problem. Just in case someone came here
for that!
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Dear Kat, thank you for leaving a feedback. We found that cases 2x/3 and 1/3*x^2 meet conditions of the question. In other words, expert's solution is not wrong.
I think for part b of this problem, they meant to say (x²)/3, in which case the answer to b is 1/9. Because the integral from 0 to 1 of (x²)/3 is (x³)/9 from 0 to 1 which equals 1/9. At least that's how my stats professor solved this problem. Just in case someone came here for that!
Leave a comment