When the decimal point of a certain positive decimal number is moved four places to the right, the new number is four times the reciprocal of the original number. What is the original number?
I need to find a decimal number x such that moving the decimal point four places to the right gives me 4/x. This means that 10^4 * x = 4/x, or x^2 = 4/10^4. Taking the square root of both sides, I get x = plus or minus 2/100. However, x has to be positive, so I can eliminate the negative option. Therefore, the original number is 0.02.

