Arailroad crew can lay 7 miles of track each day. they need to lay 203 miles of track. the length, l (in miles), that is left to lay after d days is given by the
following function.(d) =203-7d (also asks how many miles to lay after 18 days and how many days will it take to lay all the track)

Use the given degree of confidence and sample data to construct a confidence interval for the population mean mu . assume that the population has a normal distribution. a laboratory tested twelve chicken eggs and found that the mean amount of cholesterol was 185 milligrams with sequals 17.6 milligrams. a confidence interval of 173.8 mgless than muless than 196.2 mg is constructed for the true mean cholesterol content of all such eggs. it was assumed that the population has a normal distribution. what confidence level does this interval represent?