Using the results below:
M1 = 18.57, M2 = 18.33, SM1-M2 = 0.97, tcv = 1.997
1. Calculate a 95% confidence interval estimating the true difference between the population means. Write the final answer in brackets [x.xx, x.xx].
2. Based on your answer, explain whether there is a significant difference between the two population means. What about your answer tells you whether there is a significant difference or not?