Question 1116916: 3.1 It is estimated that 30% of all drivers have some kind of medical aid in South Africa. What is the
probability that in a sample of 10 drivers:
3.1.1 Exactly 4 will have a medical aid.
3.1.2 At least 2 will have a medical aid.
3.1.3 More than 9 will have a medical aid.
3.2 Sun Couriers, a parcel delivery company, has found that the delivery time of parcels to clients in
the Durban metropolitan area after airport collection is normally distributed with a mean
delivery time equal 45minutes (µ = 45) and a standard deviation of 8 minutes (α=8).
For a newly arrived consignment at Durban airport, what is the probability that a randomly
selected parcel will take: Between 45 and 51 minutes to deliver to the client
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! 1: 10C4(.3)^4*.7^6=0.2001
2: 10C2(.3^2)*.7^8=0.2335
3: That is all 10, which is .3^10=0.0000059
z=(x-mean)/sd
z=(51-45)/8=0.75
probability z is between 0 and 0.75, since 45 is z=0
This is 0.2734
|
|
|
