A man deposits $\mathrm{\$}18,000$ at the beginning of each year for 10 years in an account paying $8\mathrm{\%}$ compounded annually. He then puts the total amount on deposit in another account paying $9\mathrm{\%}$ compounded semiannually for another 9 years. Find the final amount on deposit after the entire 19-year period.

He will have a final amount of $\mathrm{\$}◻$ after the entire 19-year period. (Simplify your answer. Round to the nearest cent as needed.)

Step 1 ：For the first 10 years, the man deposits $18,000$ at the beginning of each year in an account paying $8\mathrm{\%}$ compounded annually. The future value of these deposits can be calculated using the formula for the future value of a series of annuity payments made at the beginning of each period: $FV=P\times \left(\frac{(1+r{)}^n-1}{r}\right)$, where $P$ is the payment amount, $r$ is the interest rate per period, and $n$ is the number of periods. Substituting the given values, we get $FV=18000\times \left(\frac{(1+0.08{)}^{10}-1}{0.08}\right)$.

Step 2 ：Calculating the above expression, we get $FV\approx \mathrm{\$}245,886.58$. This is the total amount the man has in his account after 10 years.

Step 3 ：For the next 9 years, the man puts the total amount on deposit in another account paying $9\mathrm{\%}$ compounded semiannually. The future value of this deposit can be calculated using the formula for the future value of a single lump sum compounded more than once per year: $FV=P\times (1+r/n{)}^{nt}$, where $P$ is the principal amount, $r$ is the annual interest rate, $n$ is the number of times interest is compounded per year, and $t$ is the time in years. Substituting the given values, we get $FV=245886.58\times (1+0.09/2{)}^{2\times 9}$.

Step 4 ：Calculating the above expression, we get $FV\approx \mathrm{\$}593,848.86$. This is the total amount the man has in his account after the entire 19-year period.

Step 5 ：So, the man will have a final amount of $\boxed{{\displaystyle \mathrm{\$}593,848.86}}$ after the entire 19-year period.