The question doesn't specify the number of years so I'll calculate the amount after 5, 10, 15, 20 and 25 years.
We can do this by working out the growth = (1+R)^N=1.06^N
5: 1.3382; 10: 1.7908; 15: 2.3966; 20: 3.2071; 25: 4.2919.
Multiply each of these by $500,000:
5: $669,112.79; 10: $895,423.85; 15: $1,198,279.10; 20: $1,603,567.74; 25: $2,145,935.36.
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