A company with a large fleet of cars hopes to keep gasoline costs down and sets a goal of attaining a fleet average of at least 26 miles per gallon. To see if the goal is being met, they check the gasoline usage for 50 company trips chosen at random, finding a mean of 25.02 mpg and a standard deviation of 4.83 mpg. We construct a 90% confidence interval for μ is:(23.87, 26.15). which of the following conclusions on the true average of mpg is correct? a. we are 90% confident that the true average mph is within (23.87,26.15) b. The probability that the true population mean is between 23.87 and 26.15 is 90%. c. We are 90% confident that the mean can be calculated. d. We are 90% confident that the sample average mph is within (23.87.26.15).