In 1963, the number of cars in the U. S. was about 1.7 million. By 1988, it had increased to about 2.9 million. Write an exponential function in the form y = abx that could be used to model the number of cars y in millions for 1963 to 1988. Write the equation in terms of x, the number of years since 1963. Round the value of b to the nearest thousandth.