For the given probability mass function of X, the mean is 3.5 and the standard deviation is 1.708.
- A discrete random variable X's probability mass function (PMF) is a function over its sample space that estimates the likelihood that X will have a given value. f(x)=P[X=x].
- The total of all potential values for a random variable X, weighted by their relative probabilities, is known as the mean (or expected value E[X]) of that variable.
- Mean(μ) = 1(1/6) + 2(1/6) + 3(1/6) + 4(1/6) + 5(1/6) + 6(1/6).
- Mean(μ) = (1+2+3+4+5+6)/6
- Mean(μ) = 21/6
- Mean(μ) = 3.5
- The square root of the variance of a random variable, sample, statistical population, data collection, or probability distribution represents its standard deviation. It is denoted by 'σ'.
- A random variable's variance (or Var[X]) is a measurement of the range of potential values. It is, by definition, the squared expectation of the distance between X and μ. It is denoted by 'σ²'.
- σ² = E[X²]−μ²
- σ² = [1²(1/6) + 2²(1/6) + 3²(1/6) + 4²(1/6) + 5²(1/6) + 6²(1/6)] - (3.5)²
- σ² = [(1² + 2²+ 3² + 4²+ 5²+ 6²)/6] - (3.5)²
- σ² = [(1 + 4 + 9 + 16 + 25 + 36)/6] - (3.5)²
- σ² = (91/6) - (3.5)²
- σ² = 15.167-12.25
- σ² = 2.917
- σ = √2.917
- Standard deviation (σ) = 1.708
To learn more about variance, visit :
brainly.com/question/14116780
#SPJ9
Multiply both sides by 10.
2b=990
divide both sides by 2
b= 495
5x5 - 10x = 0
5x5 - 10x = 5x • (x4 - 2)
Equate real part and imaginary part:
LHS:
real part -- 12
imaginary part -- 5y
RHS:
real part = 4x
imaginary part = 25
Equating::
12 = 4x
x = 12/4
x = 3
Again:
5y = 25
y = 25/5
y = 5
So,
x = 3
y = 5
35x=245
so you would divide both sides by 35
x=7
so it would take her 7 weeks or 1 month and 3 weeks to pay her friend back
Brainliest please
