Answer: Well its not GREAT context but it should be 8 divided by 1/2=s
The third one I think but I am not sure
The probability of the sample is 0.5 or 50%
<u>Explanation:</u>
Given:
Mean, μ = 20
Standard deviation, δ = 1.3
Probability of sample being less than 20.1 = ?
P (x < 20.1) = 20.1 - μ / δ √n
P (x < 20.1) = 
= 0.0098
P( x < 20.1) = P(z < 0.0098)
P (z < 0.0098) = 0.5
The value of P is found out using a z score table.
Therefore, probability of the sample is 0.5 or 50%
100/13.5 + 24 = 31.41 approximitely