Question

A flourist determines the probabilities for the number of flower arrangements they
deliver each day.
X
6 7 8 9 10
P(X)
0.2 0.2 a 0.2 0.1
(i) Find a.
(ii) Calculate the expected value and the standard deviation.
(iii) Approximately how many arrangements should the flourist expect to deliver
each week?

Answer 1

Answer:

To calculate the standard deviation (σ) of a probability distribution, find each deviation from its expected value, square it, multiply it by its probability, add the products, and take the square root.