To find out how much Alvin's family needs to pay, we first need to calculate how much Alvin will save in two years.
Alvin saves $250 a month for 24 months (2 years): \[ \text{Total savings} = 250 , \text{(savings per month)} \times 24 , \text{(months)} = 6,000 \]
Now, we subtract Alvin's savings from the total cost of the training to find out how much his family needs to contribute: \[ \text{Family contribution} = 9,500 , \text{(total cost)} - 6,000 , \text{(savings)} = 3,500 \]
Thus, Alvin's family will need to pay $3,500.