Answer:
a
[tex]E(Z) = 202 [/tex]
b
[tex]E(Z) = 198[/tex]
c
[tex]E(Z) = -140 [/tex]
Step-by-step explanation:
From the question we are told that
The mean of X is [tex] E(X) = 20[/tex]
The standard deviation of X is [tex]s_1 = 5[/tex]
The mean of Y is [tex]\= y = 40[/tex]
The standard deviation of Y is [tex]s_2 = 10[/tex]
Considering question a
Generally the mean of Z = 2 + 10X. is mathematically represented
[tex]E(Z) = E[2 + 10X ][/tex]
=> [tex]E(Z) = 2 + 10 E(X)[/tex]
=> [tex]E(Z) = 2 + 10 * 20 [/tex]
=> [tex]E(Z) = 202 [/tex]
Considering question b
Generally the mean of Z = 10X - 2.. is mathematically represented
[tex]E(Z) = E[10X -2 ][/tex]
=> [tex]E(Z) = 10E(X) - 2[/tex]
=> [tex]E(Z) = 10* 20 - 2[/tex]
=> [tex]E(Z) = 200 - 2[/tex]
=> [tex]E(Z) = 198[/tex]
Considering question c
Generally the mean of -3X - 2Y is mathematically represented
[tex]E(Z) = E[-3X -2Y ][/tex]
[tex]E(Z) = -3 E(X) -2E(Y) [/tex]
=> [tex]E(Z) = -3 * 20 -2* 40 [/tex]
=> [tex]E(Z) = -140 [/tex]
