Respuesta :
Answer:
a) P(X > 50.2) = 0.90
b) P(50.3 < X < 50.8) = 0.25
c) P(X+Y >29) = 0.9167
Step-by-step explanation:
From the given information:
[tex]f(x) = \dfrac{1}{b-a} \ \ \ \ a<x<b[/tex]
[tex]f(x) = \dfrac{1}{52.0-50.0} \ \ \ \ 50.0<x<52.0[/tex]
[tex]f(x) = \dfrac{1}{2} \ \ \ \ 50.0<x<52.0[/tex]
a)
Let X be the random variable that follows a uniform distribution.
Such that [tex]X \sim U (50.0, 52.0)[/tex]
where;
a = 50
b = 52
[tex]P(X> 50.2) = \dfrac{b - x}{b-a}[/tex]
[tex]P(X> 50.2) = \dfrac{52 - 50.2}{52-50}[/tex]
[tex]P(X> 50.2) = \dfrac{1.8}{2.0}[/tex]
P(X > 50.2) = 0.90
b.)
To find the probability that the class length is between 50.3 and 50.8 min.
i.e.
[tex]P(50.3 <X<50.8) = \dfrac{(X_2-X_1)}{(b-a)}[/tex]
[tex]P(50.3 <X<50.8) = \dfrac{(50.8-50.3)}{(52-50)}[/tex]
[tex]P(50.3 <X<50.8) = \dfrac{(0.5)}{(2)}[/tex]
P(50.3 < X < 50.8) = 0.25
c)
Given that:
the interval = (101,16)
The probability that the sum of 2 independent observations of X is greater than 29 can be computed as follows.
here;
[tex]c = \dfrac{a+b}{2}[/tex]
where;
a = 10*2 = 20
b = 16*2 = 32
[tex]c = \dfrac{20+32}{2}[/tex]
c = 52/2
c =26
The required probability:
[tex]P(X+Y >29) = 1 - \dfrac{(b-x)\times 2}{(b-a) \times (b - c)}[/tex]
[tex]P(X+Y >29) = 1 - \dfrac{(32-29)\times 2}{(32-20) \times (32 - 26)}[/tex]
[tex]P(X+Y >29) = 1 - \dfrac{(3)\times 2}{(12) \times (6)}[/tex]
[tex]P(X+Y >29) = 1 - \dfrac{6}{72}[/tex]
P(X+Y >29) = 1 - 0.0833
P(X+Y >29) = 0.9167