This preview shows page 1. Sign up to view the full content.
Unformatted text preview: endently distributed. Note
that the sum of two normally distributed random variables is also normally
Let X1 be the time taken for the first stage and X2 the time taken for the second
stage. Then Y = X1 + X2 is the time taken to complete an article.
(a) What are the mean and standard deviation of the total time to
manufacture the article?
() ( ) () ( (
) ) (
( ) ) (
Note that independence is used in the calculation of the Var(Y) (b) What proportion of articles will be completed in 35-45 minutes?
( ) ( ) ( )
( ) 6. Project Review: Be prepared to discuss the progress that you have made
with the Project. You should at least have some summary statistics and ideas
for useful graphical display of the data...
View Full Document