The pooled variance is a measure of the variation between two groups of data and can be calculated by taking the weighted average of the variances of each group. To calculate the pooled variance, first calculate the variance of each group, then multiply each variance by the number of data points in the group. After that, add the two results together and divide by the total number of data points in both groups. This will give you the pooled variance.
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p {
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#words {
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line-height: 1.75;
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#words_calc {
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max-width: 550px;
margin: 25px auto;
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#words_calc input {
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.label_radio {
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Sample 1
Sample 2
Pooled variance = 59.905303
//set summary table to hidden to start
var summary_display = document.getElementById(“summary_table”);
summary_display.style.display = “none”;
//find which radio button is checked
function check() {
if (document.getElementById(‘raw’).checked) {
var table_display = document.getElementById(“words_table”);
table_display.style.display = “block”;
var summary_display = document.getElementById(“summary_table”);
summary_display.style.display = “none”;
} else {
var table_display = document.getElementById(“words_table”);
table_display.style.display = “none”;
var summary_display = document.getElementById(“summary_table”);
summary_display.style.display = “block”;
}
} //end check
//perform one-sample t-test
function calc() {
if (document.getElementById(‘summary’).checked) {
var s1 = +document.getElementById(‘s1’).value;
var n1 = +document.getElementById(‘n1’).value;
var s2 = +document.getElementById(‘s2’).value;
var n2 = +document.getElementById(‘n2’).value;
var df = n1-(-1*n2)-2;
var pooled = Math.sqrt(((n1-1)*Math.pow(s1,2) – (-1*((n2-1)*Math.pow(s2,2))))/df);
var pooled2 = pooled*pooled;
document.getElementById(‘pooled’).innerHTML = pooled2.toFixed(6);
} else {
var raw1 = document.getElementById(‘rawData1’).value.split(‘,’).map(Number);
var raw2 = document.getElementById(‘rawData2’).value.split(‘,’).map(Number);
var s1 = math.std(raw1);
var n1 = raw1.length;
var s2 = math.std(raw2);
var n2 = raw2.length;
var df = n1-(-1*n2)-2;
var pooled = Math.sqrt(((n1-1)*Math.pow(s1,2) – (-1*((n2-1)*Math.pow(s2,2))))/df);
var pooled2 = pooled*pooled;
document.getElementById(‘pooled’).innerHTML = pooled2.toFixed(6);
}
//output results
}