A forester wishes to estimate the mean growth of seedlings in a large timber plot since last year. A random sample of 100 seedlings is taken and it is found that the one-year growth yields a mean of 12.8 cm. The standard deviation for all of the seedling is 2.5 cm. Find a 95% confidence interval for the average growth of all seedlings in the plot. If your answers are irrational, round according to the values in the problem. cm to cm