Home > Statistical Methods calculators > Combined Mean and Standard deviation calculator

Method and examples
1. Find Combined Mean and Standard deviation
Method
 Type your data, for seperator you can use space or tab for sample click random button OR Rows : Click On Generate

Combined Sd Method:
1. Find Combined mean bar X_(12)
2. Find Combined Sd (sigma_(12) = sqrt(( N_1 * (sigma_1^2 + d_1^2) + N_2 * (sigma_2^2 + d_2^2) )/( N_1 + N_2 )))
3. Find Combined Sd (sigma_(12) = sqrt(((N_1 - 1) * sigma_1^2 + (N_2 - 1) * sigma_2^2 + (N_1 * N_2)/(N_1 + N_2) * (bar x_1^2 + bar x_2^2 - 2 bar x_1 bar x_2))/(N_1 + N_2 - 1)))
1. Find Combined Mean and Standard deviationN_1=40,bar X_1=10,sigma_1=1
N_2=60,bar X_2=15,sigma_2=2

2. Find Combined Mean N_1=80,bar X_1=520
N_2=20,bar X_2=420

3. Find Combined Mean N_1=20,bar X_1=50
N_2=50,bar X_2=12

4. Find Combined Mean and Standard deviationN_1=40,bar X_1=400,sigma_1=1
N_2=60,bar X_2=900,sigma_2=4

5. Find Combined Mean N_1=80,bar X_1=41600
N_2=20,bar X_2=8400

6. Find Combined Mean N_1=20,bar X_1=1000
N_2=50,bar X_2=600

2. Find X2 from Combined Mean X12 and X1
 Combined Mean X12 = , N1 = , X1 = , N2 = , find X2
1. Combined Mean bar X_(12) = 40, bar X_1 = 10 , N_1 = 1, N_2 = 60, find bar X_2
2. Combined Mean bar X_(12) = 80, bar X_1 = 520 , N_1 = 20, N_2 = 420, find bar X_2
3. Combined Mean bar X_(12) = 20, bar X_1 = 50 , N_1 = 50, N_2 = 12, find bar X_2
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