probability thing

prob = 75
amount = 500

--script
tab = {}
probb = 0
for i=1,prob do
    table.insert(tab,i)
end

for i=1,amount do
    local randomnumber = math.random(1,100)
    local hecc = false
    for i=1,#tab do
        if tab[i] == randomnumber then
            hecc = true
            break
        end
    end
    if hecc == true then
        probb = probb + 1
    end
end

print(probb.." out of "..amount..", with an actual probability of: "..probb/amount.."%")