A certain counselor wants to compare mean IQ scores for two different social groups. A random sample of 13 IQ scores from group 1 showed a mean of 114 and a standard deviation of 16 , while an independently chosen random sample of IQ scores from group 2 showed a mean of 105 and a standard deviation of 14. Assuming that the populations of IQ scores are normally distributed for each of the groups and that the variances of these populations are equal, construct a 95% confidence interval for the difference mu1 - mu2 between the mean mu1 of IQ scores of group and the mean mu2 of IQ scores of group. Then find the lower limit and upper limit of the confidence interval.