中心极限定理计算器
中心极限定理指出,如果样本量足够大,即使总体分布不正态,样本均值的抽样分布也近似正态。中心极限定理还指出,抽样分布将具有以下属性:
1.抽样分布的均值将等于总体分布的均值:
x = µ
2.抽样分布的标准差等于总体分布的标准差除以样本量:
s = σ / √n
要查找给定样本的样本均值和标准差,只需在下面输入必要的值,然后单击“计算”按钮即可。
样本均值 ( x ) = 17
样本标准差 (s) = 0.8
function calc() {
//get input degrees of freedom, t-value var n = document.getElementById('n').value*1; var pop_mean = document.getElementById('pop_mean').value*1; var pop_sd = document.getElementById('pop_sd').value*1;
//calculate sample mean and sample standard deviation var sample_mean = pop_mean; var sample_sd = pop_sd / Math.sqrt(n);
//output values document.getElementById('sample_mean').innerHTML = sample_mean.toFixed(5); document.getElementById('sample_sd').innerHTML = sample_sd.toFixed(5); }