10. Hydrological Statistics

Question 1

What is the relative frequency of event ‘A’

Answer 1

N(A) / N

i.e. number of occurrences of A / total occurrences

Question 2

What is a PDF? What is its use?

Answer 2

Probability density function,

Used to estimate the probability of events that have not been observed

Question 3

What is the formula for z i.e. how do you normalise x?

Answer 3

z = (x - µ) / sigma
where µ = mean
sigma = standard deviation

Question 4

What is Guthrie’s dad’s profession?

Answer 4

Dentist