value not being assigned to the right one

When I input a value that is less than 3 and run my code, the cost is 5.00 instead of 2.50. What is the mistake and how do I fix it?

if (weight < 3)   {
    cost = 2.50
    total = weight * cost
}
if (3 < weightOfPackage < 9)   {
    cost = 5.00
    total = weight * cost
}