Which expression represents the phrase, "One-third the sum of 12 and a number?

a.) 1 /3 ( 12 ) + x
b.) 1 / 3x + 12
c.) 1 / 3 + 12 + x
d.) 1 / 3 ( 12 + x )

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?