a) means what is the probability of P occurring once Q has occurred. That is 9/24 which is 3/8.
b) is 14/24 which is 7/12.
Please inform me if I gave you the correct answers :)
Standard error of the mean is computed by:
Standard error = SD/ sqrt N
Where:
N is the sample size
SD is the standard deviation
To get the standard deviation, you need to get the sqrt of
the variance = sqrt 9 = 3
So plugging in our data:
Standard error = 3 / sqrt (16)
= 0.75
