Recall the car dealer interest rate example in Example $4\mathrm{.}4.$ Use a while $()$ loop to iteratively calculate the interest rate i which satisfies the fixed$-$point equation

i $=11-(1+$ i$)-20)/19.$

Use a starting guess of i $=0\mathrm{.}006.$ Stop the calculation when two successive values of the interest rate are less than $0\mathrm{.}000001$ apart.