a+b+c = 73 (a is shortest side, b is second shortest side, c is longest side)
c = a+b-5
c = 2a+8
b = a+13
2a+8+a+13+a = 73
4a+21=73
4a = 52
a = 13
b = 26
c = 34
However when you plug that back in, you don't get a triangle, so I think you are missing something
Answer:
a) c=3/4
b) for -1<x<1
F(x) = (3/4) ( x + (2-x^3)/3 )
c)
E(x)=0
Var(x) = 1/5
Step-by-step explanation:
Hi!
a)
In order to f(x) be a probability density function it must be normalized, which means that its integral must be equal to 1:

Since f(x) is zero for x>1 and x<-1

Therefore:
c=3/4
b)
The cumulative distribution fucntion F(x) can be obtained integrating f(x) from -∞ to x:
Since f(x) = 0 for x<-1
F(x) = 0 for x<-1
for -1<x<1:

for x>1
F(x)=1
c)
The mean E(x) can be found integrating xf(x)

We can easily infer that the mean must be zero, since f(x) is an even function and thus xf(x) is an odd function integrated in a simetric interval:
E(x) = 0
The variance of x, Var(x), can be evaluated integrating (x-E(x))^2f(x), since E(x)=0:

Since c=3/4
Var(x) = 1/5
57% rounded. Pretty sure that's it
Answer: 1,38
Step-by-step explanation: Because 48,345 ÷ 34,886 = 1,385799461101875, so I rounded off to 1,38