Answer:
3.14
Step-by-step explanation:
Answer: Saturday
Step-by-step explanation:
Saturday is at the highest point meaning it has less empty tables
To solve for x you need to get it by itself
start by subtracting y
3/4x=e-y
then divide by 3/4 or multiply by 4/3
so, x=(4(e-y))/3
distribute
x=(4e-4y)/3 or x=4/3e-4/3y
a.
![f_{X,Y,Z}(x,y,z)=\begin{cases}Ce^{-(0.5x+0.2y+0.1z)}&\text{for }x\ge0,y\ge0,z\ge0\\0&\text{otherwise}\end{cases}](https://tex.z-dn.net/?f=f_%7BX%2CY%2CZ%7D%28x%2Cy%2Cz%29%3D%5Cbegin%7Bcases%7DCe%5E%7B-%280.5x%2B0.2y%2B0.1z%29%7D%26%5Ctext%7Bfor%20%7Dx%5Cge0%2Cy%5Cge0%2Cz%5Cge0%5C%5C0%26%5Ctext%7Botherwise%7D%5Cend%7Bcases%7D)
is a proper joint density function if, over its support,
is non-negative and the integral of
is 1. The first condition is easily met as long as
. To meet the second condition, we require
![\displaystyle\int_0^\infty\int_0^\infty\int_0^\infty f_{X,Y,Z}(x,y,z)\,\mathrm dx\,\mathrm dy\,\mathrm dz=100C=1\implies \boxed{C=0.01}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cint_0%5E%5Cinfty%5Cint_0%5E%5Cinfty%5Cint_0%5E%5Cinfty%20f_%7BX%2CY%2CZ%7D%28x%2Cy%2Cz%29%5C%2C%5Cmathrm%20dx%5C%2C%5Cmathrm%20dy%5C%2C%5Cmathrm%20dz%3D100C%3D1%5Cimplies%20%5Cboxed%7BC%3D0.01%7D)
b. Find the marginal joint density of
and
by integrating the joint density with respect to
:
![f_{X,Y}(x,y)=\displaystyle\int_0^\infty f_{X,Y,Z}(x,y,z)\,\mathrm dz=0.01e^{-(0.5x+0.2y)}\int_0^\infty e^{-0.1z}\,\mathrm dz](https://tex.z-dn.net/?f=f_%7BX%2CY%7D%28x%2Cy%29%3D%5Cdisplaystyle%5Cint_0%5E%5Cinfty%20f_%7BX%2CY%2CZ%7D%28x%2Cy%2Cz%29%5C%2C%5Cmathrm%20dz%3D0.01e%5E%7B-%280.5x%2B0.2y%29%7D%5Cint_0%5E%5Cinfty%20e%5E%7B-0.1z%7D%5C%2C%5Cmathrm%20dz)
![\implies f_{X,Y}(x,y)=\begin{cases}0.1e^{-(0.5x+0.2y)}&\text{for }x\ge0,y\ge0\\0&\text{otherwise}\end{cases}](https://tex.z-dn.net/?f=%5Cimplies%20f_%7BX%2CY%7D%28x%2Cy%29%3D%5Cbegin%7Bcases%7D0.1e%5E%7B-%280.5x%2B0.2y%29%7D%26%5Ctext%7Bfor%20%7Dx%5Cge0%2Cy%5Cge0%5C%5C0%26%5Ctext%7Botherwise%7D%5Cend%7Bcases%7D)
Then
![\displaystyle P(X\le1.375,Y\le1.5)=\int_0^{1.5}\int_0^{1.375}f_{X,Y}(x,y)\,\mathrm dx\,\mathrm dy](https://tex.z-dn.net/?f=%5Cdisplaystyle%20P%28X%5Cle1.375%2CY%5Cle1.5%29%3D%5Cint_0%5E%7B1.5%7D%5Cint_0%5E%7B1.375%7Df_%7BX%2CY%7D%28x%2Cy%29%5C%2C%5Cmathrm%20dx%5C%2C%5Cmathrm%20dy)
![\approx\boxed{0.12886}](https://tex.z-dn.net/?f=%5Capprox%5Cboxed%7B0.12886%7D)
c. This probability can be found by simply integrating the joint density:
![\displaystyle P(X\le1.375,Y\le1.5,Z\le1)=\int_0^1\int_0^{1.5}\int_0^{1.375}f_{X,Y,Z}(x,y,z)\,\mathrm dx\,\mathrm dy\,\mathrm dz](https://tex.z-dn.net/?f=%5Cdisplaystyle%20P%28X%5Cle1.375%2CY%5Cle1.5%2CZ%5Cle1%29%3D%5Cint_0%5E1%5Cint_0%5E%7B1.5%7D%5Cint_0%5E%7B1.375%7Df_%7BX%2CY%2CZ%7D%28x%2Cy%2Cz%29%5C%2C%5Cmathrm%20dx%5C%2C%5Cmathrm%20dy%5C%2C%5Cmathrm%20dz)
![\approx\boxed{0.012262}](https://tex.z-dn.net/?f=%5Capprox%5Cboxed%7B0.012262%7D)