How much must Harry’s hardware deposit at 5.5% interest for 90 days in order to earn $800 interest?

1. Identify the given values:

- Interest earned: I = 800

- Annual interest rate: R = 0.055

- Time period: T=\frac{90}{365}

2. Use the simple interest formula:

P = \frac{I}{RT}

3. Substitute the values:

P=\frac{800}{0.055\times\frac{90}{35}}

4. Calculate the principal amount:

P=\frac{800\times365}{0.055\times90}\approx58989.899

Therefore, Harry's hardware must deposit approximately 58989.899 dollars.