xamples: 5.23 Calculate how long, to the next whole year, it will take for an investment of R2 000 to reach a value of R3 500 at an interest rate of \( 12 \% \) per year, compounded monthly.

Suppose that the walking step lengths of adult males are normally distributed with a mean of 2.3 feet and a standard deviation of 0.4 feet. A sample of 83 men's step lengths is taken. Step 1 of 2 : Find the probability that an individual man's step length is less than 2.1 feet. Round your answer to 4 decimal places, if necessary.

(b) \( \int \sin ^{4}(3 x) d x \)

Find the base of 'a parallelogram with a height of 10.5 feet and an area of \( 189 \mathrm{ft}^{2} \).

\( 7 ( x + y ) = 7 \quad + 7 \)

Solve the system by either the addition method or the substitution method. \( \left\{\begin{array}{l}3 x+5 y=10 \\ 2 x-6 y=-48.4\end{array}\right. \) Select the correct choice below and, if necessary, fill in the answer box within your choice. A. The solution is \( \square \). (Simplify your answer. Type an ordered pair. \( ) \) B. There are infinitely many solutions; \( \{(x, y) \mid 3 x+5 y=10\} \) or \( \{(x, y) \mid 2 x-6 y=-48,4\} \) C. There is no solution; \( \} \) or \( \varnothing \).