Ralph is driving from his home to his grandmother’s house at an average rate of 40 miles per hour (mph). he had driven 6 miles when his sister maria left their house and began driving along the same route. at what average rate, in miles per hour, is maria driving if she catches up with ralph in 1 1/2 hours?

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?