Answer:
Question 1: ![P ( B | Y ) = \frac{ P ( B and Y)}{ P (Y)} = \frac{ \frac{2}{16}}{ \frac{4}{16}} = \frac{1}{2}](https://tex.z-dn.net/?f=P%20%28%20B%20%7C%20Y%20%29%20%3D%20%5Cfrac%7B%20P%20%28%20B%20and%20Y%29%7D%7B%20P%20%28Y%29%7D%20%3D%20%5Cfrac%7B%20%5Cfrac%7B2%7D%7B16%7D%7D%7B%20%5Cfrac%7B4%7D%7B16%7D%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D)
Question 2:
A. ![P ( Y | B ) = \frac{ P(Y and B) }{ P(B) } = \frac{ \frac{2}{16} }{ \frac{6}{16} } = \frac{1}{3}](https://tex.z-dn.net/?f=P%20%28%20Y%20%7C%20B%20%29%20%3D%20%5Cfrac%7B%20P%28Y%20and%20B%29%20%7D%7B%20P%28B%29%20%7D%20%3D%20%5Cfrac%7B%20%5Cfrac%7B2%7D%7B16%7D%20%7D%7B%20%5Cfrac%7B6%7D%7B16%7D%20%7D%20%3D%20%5Cfrac%7B1%7D%7B3%7D)
B. ![P( Z | B ) = \frac{ P ( Z and B)}{ P (B)}= \frac{ \frac{1}{16} }{ \frac{6}{16} } = \frac{1}{6}](https://tex.z-dn.net/?f=P%28%20Z%20%7C%20B%20%29%20%3D%20%5Cfrac%7B%20P%20%28%20Z%20and%20B%29%7D%7B%20P%20%28B%29%7D%3D%20%5Cfrac%7B%20%5Cfrac%7B1%7D%7B16%7D%20%7D%7B%20%5Cfrac%7B6%7D%7B16%7D%20%7D%20%3D%20%5Cfrac%7B1%7D%7B6%7D)
C. ![P((Y or Z)|B) = \frac{ P ((Y or Z) and B)}{P(B)}= \frac{ \frac{3}{16}}{ \frac{6}{16}}= \frac{1}{2}](https://tex.z-dn.net/?f=P%28%28Y%20or%20Z%29%7CB%29%20%3D%20%5Cfrac%7B%20P%20%28%28Y%20or%20Z%29%20and%20B%29%7D%7BP%28B%29%7D%3D%20%5Cfrac%7B%20%5Cfrac%7B3%7D%7B16%7D%7D%7B%20%5Cfrac%7B6%7D%7B16%7D%7D%3D%20%5Cfrac%7B1%7D%7B2%7D)
Step-by-step explanation:
Conditional probability is defined by
![P(A|B)= \frac{P(A and B)}{P(B)}](https://tex.z-dn.net/?f=P%28A%7CB%29%3D%20%5Cfrac%7BP%28A%20and%20B%29%7D%7BP%28B%29%7D)
with P(A and B) beeing the probability of both events occurring simultaneously.
Question 1:
B: Baseball League Championships won, beeing
![P ( B ) = \frac{ 6 }{16}](https://tex.z-dn.net/?f=P%20%28%20B%20%29%20%3D%20%5Cfrac%7B%206%20%7D%7B16%7D)
Y: Championships won by the 10 - 12 years old, beeing
![P ( Y)= \frac{ 4 }{ 16 }](https://tex.z-dn.net/?f=P%20%28%20Y%29%3D%20%5Cfrac%7B%204%20%7D%7B%2016%20%7D)
then
P( B and Y)= \frac{ 2 }{ 16 }[/tex]
By definition,
![P ( B | Y ) = \frac{ P ( B and Y)}{ P (Y)} = \frac{ \frac{2}{16} }{ \frac{4}{16} } = \frac{1}{2}](https://tex.z-dn.net/?f=P%20%28%20B%20%7C%20Y%20%29%20%3D%20%5Cfrac%7B%20P%20%28%20B%20and%20Y%29%7D%7B%20P%20%28Y%29%7D%20%3D%20%5Cfrac%7B%20%5Cfrac%7B2%7D%7B16%7D%20%7D%7B%20%5Cfrac%7B4%7D%7B16%7D%20%7D%20%20%3D%20%5Cfrac%7B1%7D%7B2%7D)
Question 2.A:
Y: Championships won by the 10 - 12 years old, beeing
![P ( Y)= \frac{ 4 }{ 16 }](https://tex.z-dn.net/?f=P%20%28%20Y%29%3D%20%5Cfrac%7B%204%20%7D%7B%2016%20%7D)
B: Baseball League Championships won, beeing
![P ( B ) = \frac{ 6 }{16}](https://tex.z-dn.net/?f=P%20%28%20B%20%29%20%3D%20%5Cfrac%7B%206%20%7D%7B16%7D)
then
P( B and Y)= \frac{ 2 }{ 16 }[/tex]
By definition,
![P ( Y | B ) = \frac{ P(Y and B) }{ P(B) } = \frac{ \frac{2}{16} }{ \frac{6}{16} } = \frac{1}{3}](https://tex.z-dn.net/?f=P%20%28%20Y%20%7C%20B%20%29%20%3D%20%5Cfrac%7B%20P%28Y%20and%20B%29%20%7D%7B%20P%28B%29%20%7D%20%3D%20%5Cfrac%7B%20%5Cfrac%7B2%7D%7B16%7D%20%7D%7B%20%5Cfrac%7B6%7D%7B16%7D%20%7D%20%3D%20%5Cfrac%7B1%7D%7B3%7D)
Question 2.B:
Z: Championships won by the 13 - 15 years old, beeing
![P ( Z)= \frac{ 1 }{ 16 }](https://tex.z-dn.net/?f=P%20%28%20Z%29%3D%20%5Cfrac%7B%201%20%7D%7B%2016%20%7D)
B: Baseball League Championships won, beeing
![P ( B ) = \frac{ 6 }{16}](https://tex.z-dn.net/?f=P%20%28%20B%20%29%20%3D%20%5Cfrac%7B%206%20%7D%7B16%7D)
then
P( Z and B)= \frac{ 1 }{ 16 }[/tex]
By definition,
![P( Z | B ) = \frac{ P ( Z and B)}{ P (B)}= \frac{ \frac{1}{16} }{ \frac{6}{16} } = \frac{1}{6}](https://tex.z-dn.net/?f=P%28%20Z%20%7C%20B%20%29%20%3D%20%5Cfrac%7B%20P%20%28%20Z%20and%20B%29%7D%7B%20P%20%28B%29%7D%3D%20%5Cfrac%7B%20%5Cfrac%7B1%7D%7B16%7D%20%7D%7B%20%5Cfrac%7B6%7D%7B16%7D%20%7D%20%3D%20%5Cfrac%7B1%7D%7B6%7D)
Question 3.B
Y: Championships won by the 10 - 12 years old, beeing
![P ( Y)= \frac{ 4 }{ 16 }](https://tex.z-dn.net/?f=P%20%28%20Y%29%3D%20%5Cfrac%7B%204%20%7D%7B%2016%20%7D)
Z: Championships won by the 13 - 15 years old, beeing
![P ( Z)= \frac{ 1 }{ 16 }](https://tex.z-dn.net/?f=P%20%28%20Z%29%3D%20%5Cfrac%7B%201%20%7D%7B%2016%20%7D)
then
![P (Y or Z) = P(Y) + P(Z) = \frac{6}{16}](https://tex.z-dn.net/?f=P%20%28Y%20or%20Z%29%20%3D%20P%28Y%29%20%2B%20P%28Z%29%20%3D%20%5Cfrac%7B6%7D%7B16%7D)
B: Baseball League Championships won, beeing
![P ( B ) = \frac{ 6 }{16}](https://tex.z-dn.net/?f=P%20%28%20B%20%29%20%3D%20%5Cfrac%7B%206%20%7D%7B16%7D)
so
![P((YorZ) and B)= \frac{3}{16}](https://tex.z-dn.net/?f=P%28%28YorZ%29%20and%20B%29%3D%20%5Cfrac%7B3%7D%7B16%7D)
By definition,
![P((Y or Z)|B) = \frac{ P ((Y or Z) and B)}{P(B)}= \frac{ \frac{3}{16}}{ \frac{6}{16}}= \frac{1}{2}](https://tex.z-dn.net/?f=P%28%28Y%20or%20Z%29%7CB%29%20%3D%20%5Cfrac%7B%20P%20%28%28Y%20or%20Z%29%20and%20B%29%7D%7BP%28B%29%7D%3D%20%5Cfrac%7B%20%5Cfrac%7B3%7D%7B16%7D%7D%7B%20%5Cfrac%7B6%7D%7B16%7D%7D%3D%20%5Cfrac%7B1%7D%7B2%7D)