In a subtraction formula, it is known that the mean of the minuend, the subtrahend and the difference is 4.28, then what is the minuend.
在一道减法算式中，已知被减数、减数、差的平均数是4.28，则被减数是多少．
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4.28 * (3/2)</gadget>
<output>6.42</output>

<result>6.42</result>