In: Statistics and Probability
A study was conducted to determine if the salaries of elementary school teachers from two neighboring districts were equal. A sample of 15 teachers from each district was randomly selected. The mean from the first district was $28,900 with a standard deviation of $2300. The mean from the second district was $30,300 with a standard deviation of $2100. Assume the samples are random, independent, and come from populations that are normally distributed. Construct a 95% confidence interval for μ1 - μ2. Assume that two populations' variance are the same (σ21= σ22).