C++ 程式來實現分組資料的標準偏差
在本篇教程中,我們將討論一個實現分組資料標準偏差的程式。
為此,我們給定類區間和類的頻率。我們的任務是找到分組資料的標準偏差。
示例
#include <bits/stdc++.h> using namespace std; //finding mean of grouped data float calc_mean(float mid[], int freq[], int n){ float sum = 0, freqSum = 0; for (int i = 0; i < n; i++) { sum = sum + mid[i] * freq[i]; freqSum = freqSum + freq[i]; } return sum / freqSum; } //finding standard deviation of data float calc_deviation(float lower_limit[], float upper_limit[], int freq[], int n){ float mid[n], sum = 0, freqSum = 0, sd; for (int i = 0; i < n; i++) { mid[i] = (lower_limit[i] + upper_limit[i]) / 2; sum = sum + freq[i] * mid[i] * mid[i]; freqSum = freqSum + freq[i]; } sd = sqrt((sum - freqSum * calc_mean(mid, freq, n) * calc_mean(mid, freq, n)) / (freqSum - 1)); return sd; } int main(){ float lower_limit[] = { 50, 61, 71, 86, 96 }; float upper_limit[] = { 60, 70, 85, 95, 100 }; int freq[] = { 9, 7, 9, 12, 8 }; int n = sizeof(lower_limit) / sizeof(lower_limit[0]); cout << calc_deviation(lower_limit, upper_limit, freq, n) << endl; return 0; }
輸出
15.757
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