Well, the first one is 2/40=1/20. The 2nd one is 1/39. You multiply these to get 1/780.
Answer:
a. E(x) = 3.730
b. c = 3.8475
c. 0.4308
Step-by-step explanation:
a.
Given
0 x < 3
F(x) = (x-3)/1.13, 3 < x < 4.13
1 x > 4.13
Calculating E(x)
First, we'll calculate the pdf, f(x).
f(x) is the derivative of F(x)
So, if F(x) = (x-3)/1.13
f(x) = F'(x) = 1/1.13, 3 < x < 4.13
E(x) is the integral of xf(x)
xf(x) = x * 1/1.3 = x/1.3
Integrating x/1.3
E(x) = x²/(2*1.13)
E(x) = x²/2.26 , 3 < x < 4.13
E(x) = (4.13²-3²)/2.16
E(x) = 3.730046296296296
E(x) = 3.730 (approximated)
b.
What is the value c such that P(X < c) = 0.75
First, we'll solve F(c)
F(c) = P(x<c)
F(c) = (c-3)/1.13= 0.75
c - 3 = 1.13 * 0.75
c - 3 = 0.8475
c = 3 + 0.8475
c = 3.8475
c.
What is the probability that X falls within 0.28 minutes of its mean?
Here we'll solve for
P(3.73 - 0.28 < X < 3.73 + 0.28)
= F(3.73 + 0.28) - F(3.73 + 0.28)
= 2*0.28/1.3 = 0.430769
= 0.4308 -- Approximated
So 4 hours
1 hour=60 minutes
1 minute=60 seconds
1 hour=60 times 60 seconds=3600seconds
4 hours=3600 seconds times 4=14400seconds
so 8 out of 14400
8/14400=2/3600=1/1800
percent means parts out of100 so
x%=x/100
the reatios are equal to
1/1800=x/100
mulitply both sides by 100
100/1800=x
1/18=x
divide out
0.055555555=x
round
0.06%
B as it's Start Fraction 10 if I am reading this correctly. 50/50 between B and A
It might be 3/4, 6/5, 9/6, 12/7, 15/8
