Points:
The question is incomplete as the value of x is not given and what is required is not stated.
However, I'll assume that x = 5
Going by the details of the question, possible questions could be:
Answer:
See Explanation
Step-by-step explanation:
Given
Represent the probability with p.
So:
[tex]p = 0.8[/tex]
Solving (a): The expected number of hits.
In probability, the expected number is calculated as:
[tex]E(x) = p * x[/tex]
Substitute values for p and x
[tex]E(x) = 0.8 * 5[/tex]
Remember that 5 is an assumed value of x
[tex]E(x) = 4[/tex]
Hence, the expected number of hits when 5 missiles is fired is 4
Solving (b): Variance
In probability, variance is calculated as:
[tex]variance = x*p*(1-p)[/tex]
Substitute values for p and x
[tex]variance = 5*0.8*(1-0.8)[/tex]
[tex]variance = 5*0.8*0.2[/tex]
[tex]variance = 0.8[/tex]
Hence, the variance is 0.8
Solving (c): The standard deviation
In probability, the standard deviation is calculated as:
[tex]SD= \sqrt{Variance[/tex]
Substitute values for variance
[tex]SD= \sqrt{0.8[/tex]
[tex]SD= 0.89[/tex]
Hence, the standard deviation is 0.89