Power Plant Data. The data file power1.dat contains a power plant output in megawatts over...

Power Plant Data. The data file power1.dat contains a power plant output in megawatts over a period of 10 weeks. Each row of data contains 7 floating-point numbers that represent 1 week’s data. In developing the following programs, use symbolic constants NROWS and NCOLS to represent the number of rows and columns in the array used to store the data.

Write a function to compute and return the average value in a two-dimensional vector of type double. Assume that the corresponding function prototype is

double avgVec(const vector < &x);