Answer
The customer might pay either $19.5$ cents more or less.
Work Step by Step
The real price of $3$ $lb$ Hawaiian Kona is: $6.50 \times 3=19.50\$$
But the customer might be charged for either $3.03$ $lb$ or $2.97$ $lb$ instead (maximum and minimum). The price of $.03$ $lb$ is: $6.50\times1.03=6.695$
$6.695-6.50=0.195$ Which is $19.5$ Cent.
The customer might pay either $19.5$ cents more or less.