Technical Calculator

Pooled Variance Calculator

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What is the pooled variance?

The pooled variance is the weighted average of the two sample variances taken from the two populations. The variance is determined by taking the weighted estimates for each sample set. Divide the mean square of the two sample sets by the degrees of freedom of the two sample sets. The Pooled Variance Calculator calculates the pooled variance, standard deviation, standard error, and degrees of freedom for the data set. .

The combined model for variance is:

The model for estimating the population variance is as follows: :

\(S_p^2 = \dfrac{(n -1)S_1^2 + (n_2 - 1)S_2^2}{n_1 + n_2 - 2}\)

in which:

S = variance of the data set

n= Range of factorials

The way to Calculate Pooled Variance?

let pooled pattern trendy deviations of populations be 2 and three respectively. the dimensions of both the sample dataset are 10 and 20, then and widespread deviation of the dataset, and the usual deviation of the dataset?

Given:

pattern size (n1) = 10

pattern size (n2) = 20

pattern standard deviation (S1) = 2

pattern standard deviation (S2) = 3

Pooled Variance:

\(S_p^2 = \dfrac{(n -1)S_1^2 + (n_2 - 1)S_2^2}{n_1 + n_2 - 2}\)

\(S_p^2 = \dfrac{(10 -1)(2)^2 + (20 - 1)(3)^2}{10 + 20 - 2}\)

\(S_p^2 = \dfrac{207}{28}\)

\(S_p^2 = 7.3929\)

The expected population standard deviation for the two samples is 7.3929. You can calculate the standard deviation by taking the square root of the variance. .

Specified measure:

\(S_p^2 = 7.3929\)

Taking beneath the root of both sides

\(sqrt{(S_p)^2} = sqrt{7.3929}\)

S_p = 2.719

The Standard Deviation for the Standard Deviation is calculated after the values ​​of the variables are obtained. The variance of the pooled samples shows the variance of the values ​​of the data set.

preferred mistakes:

\(SE = S_{{\bar x_1 - \bar x_2}} = S_p \sqrt{\dfrac{1}{n_1} + \dfrac{1}{n_2}}\)

\(SE = 2.719 \sqrt{\dfrac{1}{10} + \dfrac{1}{20}}\)

\(SE = 2.719 \sqrt{0.15}\)

\(SE = 1.0531\)  

The standard errors is calculated with the aid of the Pooled Variance Calculator to locate the predicted error inside the dataset values.

Diploma of Freedom:

\(df = n_1 + n_2 - 2\)

\(df = 10 + 20 - 2\)

\(df = 28\)

The standard error is calculated with the help of the Competition Cap The degrees of freedom of the data set are the degrees of freedom that affect the data set The variable is a fixed variable. The T-Test Calculator calculates the degrees of freedom for the values ​​in a data set relative to the sample values.

How the Combined Test Works:

Let's take a look at how the Combined Test works. Some of the steps are easy for consumers to understand.

Input:

  • Choose the equal or unequal variance from the list
  • pick the summarized data or uncooked statistics
  • input the sample trendy deviation and sample size of samples
  • Hit the Calculate Button

Ouput:

  • Pooled variance, preferred deviation, standard error, and diploma of freedom