Write the $C++$ code for a void function that receives three double variables: the first two by value and the last one by reference. Name the formal parameters n$1,$ n$2,$ and answer. The function should divide the n $1$ variable by the n $2$ variable and then store the result in the answer variable. Name the function calcQuotient. Also write an$.$ appropriate function prototype for the cal CQuotient function. In addition, write a statement that invokes the calcQuotient function, passing it the num$1,$ num$2,$ and quotient variables.