A car manufacturer is interested in estimating the true mean fuel consumption in real-world city driving for one of its new models.12 new randomly selected cars are driven for a tank, and it is found that the sample mean fuel consumption is 9.4 l/100k, with a sample standard deviation ofs= 0.351.Suppose the manufacturer wishes to construct a confidence interval for mu, the true mean fuel consumption for this model under these conditions.Suppose it is reasonable to assume the fuel consumption is approximately normally distributed.

a)What is the margin of error of a 95% confidence interval for mu?

b)What is the margin of error of a 90% confidence interval for mu?