Answer:
5 weeks
Step-by-step explanation:
12/3 = 4
20/5= 4
Answer:
Hey! Is this the full question?
Step-by-step explanation:
Answer: E(Y) = 1.6 and Var(Y)=1.12
Step-by-step explanation:
Since we have given that
X 0 1 2
P(X) 0.4 0.4 0.2
Here, number of games = 2
So, 
Since 
are independent variables.
so, ![E[Y]=2E[X]\\\\Var[Y]=2Var[X]](https://tex.z-dn.net/?f=E%5BY%5D%3D2E%5BX%5D%5C%5C%5C%5CVar%5BY%5D%3D2Var%5BX%5D)
So, we get that
![E(X)=0.4\times 0+0.4\times 1+0.2\times 2=0.8\\\\and Var[x]=E[x^2]-(E[x])^2\\\\E[x^2]=0\times 0.4+1\times 0.4+4\times 0.2=1.2\\\\So, Var[x]=1.2-(0.8)^2\\\\Var[x]=1.2-0.64=0.56](https://tex.z-dn.net/?f=E%28X%29%3D0.4%5Ctimes%200%2B0.4%5Ctimes%201%2B0.2%5Ctimes%202%3D0.8%5C%5C%5C%5Cand%20Var%5Bx%5D%3DE%5Bx%5E2%5D-%28E%5Bx%5D%29%5E2%5C%5C%5C%5CE%5Bx%5E2%5D%3D0%5Ctimes%200.4%2B1%5Ctimes%200.4%2B4%5Ctimes%200.2%3D1.2%5C%5C%5C%5CSo%2C%20Var%5Bx%5D%3D1.2-%280.8%29%5E2%5C%5C%5C%5CVar%5Bx%5D%3D1.2-0.64%3D0.56)
So, E[y]=2×0.8=1.6
and Var[y]=2×0.56=1.12
Hence, E(Y) = 1.6 and Var(Y)=1.12
Part A.
7.8 is a rational number between 7.7 and 7.9.
It is rational because it can be written as a fraction of integers, such as 78/10.
Part B.
sqrt(60) = 7.75
sqrt(60) cannot be written as a fraction of integers. It is a decimal number that never ends and never repeats.
<h3>The ratio in three ways are 500 : 125 or 100 : 25 or 4 : 1</h3>
<em><u>Solution:</u></em>
Given that,
Five hundred sixth-grade students were surveyed
Which means,
sixth-grade students = 500
125 had traveled on an airplane
<em><u>What is the ratio of total sixth-grade students to the number of students who had traveled on an airplane?</u></em>
Therefore,
total sixth-grade students : students traveled on airplane = 500 : 125
<h3>Ratio = 500 : 125</h3>
Reduce to lowest terms,
Divide both sides by 5
<h3>Ratio = 100 : 25</h3>
Further reduce to simplest terms,
Divide both sides by 25
<h3>Ratio = 4 : 1</h3>
Thus the ratio in three ways are 500 : 125 or 100 : 25 or 4 : 1
