The distribution of checking account balances for customers at Independent Bank is known to be bell - shaped with a mean of $1,800 and a standard deviation of $300. Given this information, the percentage of accounts with balances between $1,500 and $2,100 will be approximately 95%.

According to the empirical rule (68-95-99.7 rule) for a bell-shaped distribution, approximately 68% of the data falls within one standard deviation of the mean. Therefore, the percentage of accounts with balances between $1,500 ($1,800 - $300) and $2,100 ($1,800 + $300) is approximately 68%, not 95%.