Fiona walks from her house to a bus stop where she gets a bus to school. Her
time,Wminutes, to walk to the bus stop is normally distributed with W-N (12^3) Fiona always leaves her house at 07:15. The first bus that she can get departs at 07:30.
a)Find the probability that it will take Fiona between minutes and
minutes to walk to the bus stop.
The length of time, minutes, of the bus journey to Fiona’s school is normally
distributed withB-N(50, σ^2) . The probability that the bus journey takes less than
60 minutes is 0.941.
b) Find σ
c) Find the probability that the bus journey takes less than 45 minutes.
If Fiona misses the first bus, there is a second bus which departs at 07:45. She
must arrive at school by 08:30 to be on time. Fiona will not arrive on time if she
misses both buses. The variablesWandBare independent.
d)
Find the probability that Fiona will arrive on time
This year, Fiona will go to school on 183 days.
e)
Calculate the number of days Fiona is expected to arrive on time.