Answer:
Year Minimum wage CPI Wage today adjusted for inflation
1938 $0.25 14 $4.57
1979 $2.90 69 $10.76
1999 $3.80 127 $7.68
$1 in 1938 is equivalent to 256/14 = $18.29 today
so $0.25 is equivalent to $18.29 x 0.25 = $4.57
$1 in 1979 is equivalent to 256/69 = $3.71 today
so $2.90 is equivalent to $3.71 x 2.90 = $10.76
$1 in 1999 is equivalent to 256/127 = $2.02 today
so $3.80 is equivalent to $2.02 x 3.80 = $7.68