Raftelis financial consulting reported that the mean quartely water bill in the US is 47.50. Some water systems are operated b public utilities while other water systems are operated by private companies. An economist pointed out that privatization does not equal competition and monompoly powers provided to public utilities are now being transfered to private companies. The water system for atlanta, georgia, is provided by a private company. A sample of 64 atlanta consumers showed a mean quarterly water bill of $51 with a sample standard deviation of $12. at a 5 percent level confidence, does atlanta sample support the conclusion that above-average rates exists for this private water system? what is your conclusion?