The Automobile Association gave the average price of unleaded petrol in Norway as 14.14 Norwegian krona (NK) per litre in January 2015. Assume this price is the population mean, and that the population standard deviation is o = 1 NK. What is the probability that the mean price for a random sample of n petrol stations is within 0.25 NK of the population mean: a. If n = 30? b. If n = 50? C. If n = 100? d. Would you recommend a sample size of 30, 50 or 100 to have at least a 0.95 probability that the sample mean is within 0.25 NK of the population mean?