Question 431234
Assuming a normal distribution, then by the empirical rule, 95% of the incomes lie within two standard deviations, or between $22,000 and $62,000.
Assuming non-normality, and using Chebyshev's theorem, then

{{{P(abs(X - 42000) <= k*10000) >= 1-1/k^2 = 0.95}}},

==> {{{1/k^2 = 0.05}}} ==> {{{k = 2sqrt(5)}}}

==>  {{{abs(X - 42000) <= 20000sqrt(5)}}}
<==> {{{42000 -  20000sqrt(5)<= X <=  42000 + 20000sqrt(5)}}}

Since the left endpoint is negative, the bounds are 0 and 86,721.36.