First find how much the rail project will increase the house value by multiplying the initial value by 25%: $400,000 * .25 = $<<400000*.25=100000>>100,000
Then add that amount to the initial value to find the new value: $100,000 + $400,000 = $<<100000+400000=500000>>500,000
Then divide the maximum amount of property tax Jenny can afford to pay by the property tax rate to find the maximum value her house can have: $15,000 / .02 = $<<15000/.02=750000>>750,000
Now subtract the house's value after the rail project from the maximum value to find how much value the improvements can have: $750,000 - $500,000 = $<<750000-500000=250000>>250,000
#### 250000