For the population of all families in Round Rock, the average number of visits to the doctor each year is, with a standard deviation. You obtain a random sample of Round Rock families who are in the city exercise program, and find that they average visits each year. Is there a significant difference in average visits to the doctor per year between the population of all Round Rock families compared to the population of families in the city exercise program?
(a) Yes, there is a significant difference.
(b) No, there is no significant difference.
(c) Cannot be determined based on the information provided.
(d) More data is needed to determine significance.