Fuel economy estimates for cars built in one particular year predicted a mean of 12.2 km per litre of fuel and a standard deviation of 2.25 km per litre of fuel for highway driving. Assuming that the mean is approximately normally distributed, use the 68 – 95 – 99.7 rule (empirical rule) to answer the following questions. Give illustration/show your calculations. (i). Approximate the percent of cars that should get less than 5.45 km/litre? (ii). How many kilometres per litre for the most efficient (i.e. highest) 2.5% of cars? A random sample of 55 cars was taken and the average kilometres covered per litre was calculated. To 4 decimal places, what is the probability that the sample mean kilometres of distance covered is less than 11.5 km/lit? Show all working including the Excel function used. A diagram may also be helpful.
Fuel economy estimates for cars built in one particular year predicted a mean of 12.2 km per
litre of fuel and a standard deviation of 2.25 km per litre of fuel for highway driving.
Assuming that the mean is approximately
(
Give illustration/show your calculations.
(i). Approximate the percent of cars that should get less than 5.45 km/litre?
(ii). How many kilometres per litre for the most efficient (i.e. highest) 2.5% of cars?
A random sample of 55 cars was taken and the average kilometres covered per litre was
calculated. To 4 decimal places, what is the
distance covered is less than 11.5 km/lit? Show all working including the Excel
A diagram may also be helpful.
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