Question

A study of petrol prices in a large city on April 1st, 2017 found that the price of E10 varied at garages across the city according to a normal distribution with a mean of $1.45 per litre and a standard deviation of 10 cents per litre.

1. (1 mark) What is the probability that a randomly selected garage in the city charged less than $1.63 per litre? (4dp)

   
   

2. What is the probability that a randomly selected garage in the city charged more than $1.43 per litre? (4dp)

   
   

3. What is the probability that a randomly selected garage charged between $1.27 and $1.62 per litre? (4dp)
   

4. (1 mark) If the price of E10 at a garage was on the 94th percentile, what was its price per litre? (2dp)

Answer 1