A.J. has 20 jobs that she must do in sequence, withthe times required to do each of these jobs beingindependent random variables with mean 50 minutesand standard deviation 10 minutes. M.J. has20 jobs that he must do in sequence, with the timesrequired to do each of these jobs being independentrandom variables with mean 52 minutes andstandard deviation 15 minutes.(a) Find the probability that A.J. finishes in lessthan 900 minutes.(b) Find the probability that M.J. finishes in lessthan 900 minutes.(c) Find the probability that A.J. finishesbefore M.J.

Review of Notes 4: i = 1, 2 ….. n j = 1, 2 ….r i ̅ ∑ ∑ ̅ ∑ ∑ ∑ ∑ ( ̅) => Overall Variation (SST total sum of squares) ∑ ∑ ( ) = {( ̅ ) ̅ ̅ } = ∑ ∑ ( ̅ ) ∑ ∑ (̅ ̅) ∑ ∑ ( ̅ )(̅ ̅) ∑ ∑ ( ̅ ) Error sum of ∑ ∑ (̅ ̅) mean sum of squares (SSE) squares (SSM Look at ∑ ∑ ( ̅ )(̅ ̅) ∑ ( ̅ ̅)∑ ( ̅ ) ∑ ̅ ∑ ∑ ( ̅) ( ) ∑ (̅ ̅) ( )