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)...

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 (Sample Joint Accounts) -

Sample 1 -

n1 = 20, s1 = $256, x1 = $1,123

Sample 2 -

n2 = 30, s2 = $300, x2 = $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 = 1.677. Assume that the population standard deviations are unknown and equal.