I wrote a small C++ program to calculate the mean and standard deviation of a given data set. Here it is:

#include <iostream> #include <cmath> using namespace std; int main (int argc, char* argv[]) { int number_of_items; cout << "How many pieces of data are in the list? "; cin >> number_of_items; float list[number_of_items]; // get all the data items cout << "Please enter the data:" << endl; int i; for (i = 1; i <= number_of_items; i++) { cout << i << ". "; cin >> list[i]; } // find the mean (average) of the data float xbar = 0; for (i = 0; i <= number_of_items; i++) xbar = xbar + list[i]; xbar = xbar / number_of_items; cout << "The mean (average) is " << xbar << "." << endl; // find the standard deviation float numerator = 0; float denominator = number_of_items; for (i = 1; i <= number_of_items; i++) numerator = numerator + pow((list[i] - xbar), 2); float standard_deviation = sqrt (numerator/denominator); cout << "The standard deviation for the given data is " << standard_deviation << "." << endl; return 0; }

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