There is interest at the american savings and loan as to whether there is a difference between average daily balances in checking accounts that are joint accounts (two or more members per account) versus single accounts (one member per account). to test this, a random sample of checking accounts was selected with the following results: single accounts joint accounts n = 20 n = 30 s = $256 s = $300 = $1,123 = $1,245 based upon these data, the critical value from the t-distribution for testing the difference between the two population means using a significance level of 0.05 is t = 1.6772.