x=1 after the first 5 years; x=2 after the another 5 years (or better said after the first 10 years in the bank); x=3 after another 5 years ( or better said after the first 15 years in the bank) and so on...
x is the number of 5 years intervals which have passed up to a moment in time :)
4150 ;
In this investment scenario, one doubling period corresponds to 5 years. This means that the investment will double in value every five years. For example, $2000 grows to $4000 after 5 years, and then to $8000 after 10 years.
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