Let the probability that a person agrees to complete the survey be 0.2. Therefore, the probability that a person does not agree is 0.8.

The probability that none of the first three people agree to complete the survey is given by:

\((0.8)^3 = 0.512\)

Thus, the probability that at least one person agrees is:

\(1 - (0.8)^3 = 1 - 0.512 = 0.488\)

Alternatively, using the binomial probability formula, the probability that exactly one, two, or three people agree can be calculated and summed:

\(P(1, 2, 3) = \binom{3}{1}(0.2)(0.8)^2 + \binom{3}{2}(0.2)^2(0.8) + (0.2)^3\)

\(= 3(0.2)(0.8)^2 + 3(0.2)^2(0.8) + (0.2)^3\)

\(= 0.384 + 0.096 + 0.008 = 0.488\)