The random variable X has mean 12 and standard deviation 3. The random variable W is defined as W=7+2X . What are the mean and s
2 answers:
Answer:
The mean and standard devaition of W are 6 and 31 respectively.
Step-by-step explanation:
Given that:
W = 7 + 2X
Variance (W) = Variance(7 + 2X)
For a term constant term, the variance is zero.
So;
W = 4 × Var(X)
W = 4 × (SD (X))²
W = 4 × (3)²
W = 4 × 9
W = 36
Thus, Variance (W) = 36
The standard deviation of W =
W =
W = 6
Also;
E(W) = E(7 +2 X)
E(W) = 7 + 2 × E(X)
where;
mean X = 12
E(W) = 7 + 2(12)
E(W) = 31
Thus, the mean and standard devaition of W are 6 and 31 respectively.
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Answer:
Option B.
Step-by-step explanation:
Integer: A non fractional complete number is known as integer. It can be either positive or negative or zero.
For examples : ...,-3,-2,-1,0,1,2,3,...
It is a clear that the difference between two consecutive integers is 1. It means we have to add 1 in the integer to get the next integer.
We need to express "next integer after the integer n" mathematically. So, we need to add 1 in n.
Required expression
Hence, the next integer after the integer n is n+1.
Therefore, the correct option is B.