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Given the p.d.f. of a continuous r.v. X , f (x) = x23 , for –1 < x < 2 and = 0 otherwise Determine c.d.f. of X hence find P( X > 0) - Mathematics and Statistics

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प्रश्न

Given the p.d.f. of a continuous r.v. X ,

f (x) = `x^2/ 3` , for –1 < x < 2 and = 0 otherwise

Determine c.d.f. of X hence find P( X > 0)

बेरीज

उत्तर

Then F(x) = ` int_(-∞)^x f (x) dx`

=` int_(-∞)^-1 f (x) dx + int_(-1)^x f (x) dx`

= 0 + `int_(-1)^x x^2/3 dx = 1/3int_(-1)^x x^2 dx`

= `1/3[x^3/3]_-1^x`

= `1/3[x^3/3-(-1/3)]`

∴ f(x) = `(x^3+1)/9`

P (X > 0) = 1 - P(X ≤ 0 )

= 1 - [F(0) - F(-1)]

= 1 - `[((0^3+1)/9)-(((-1)^3+1)/9)]`

= 1 - `(1/9-0) = 1 - 1/9=8/9`

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Types of Random Variables
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पाठ 7: Probability Distributions - Exercise 7.2 [पृष्ठ २३९]

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बालभारती Mathematics and Statistics 2 (Arts and Science) [English] 12 Standard HSC Maharashtra State Board
पाठ 7 Probability Distributions
Exercise 7.2 | Q 9.3 | पृष्ठ २३९

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