A research team is interested in the difference between serum uric acid levels in patients with and without Down's syndrome. In a large hospital for the treatment of the mentally retarded, a sample of 12 individuals with Down's syndrome yielded a mean of x1 = 4.5 mg/100 ml. In a general hospital, a sample of 15 normal individuals of the same age and sex were found to have a mean value of x2 = 3.44 mg/100 ml. If it is reasonable to assume that the two populations have a difference in means between patients with and without Down's syndrome to be (0.26, 1.94), is this evidence that there is a difference in the mean amount of serum uric acid levels in patients with and without Down's syndrome? Why or why not?