Asample of lake water was analyzed to determine the amount of metals found in the lake. the standard deviation of the sampling method was found to be ±6.0%±6.0% . the standard deviation of the analytical method used to determine the amount of metals in the sample was determined to be ±2.4%±2.4% . what is the overall standard deviation?

The overall standard deviation, s = 6.46 %

Given:

Sampling variance,

Analytical variance,

Solution:

Variance additive is given by:

                       (1)

where

s = overall variance

Also, we know that:

Standard Deviation,

Therefore the standard deviation of the sampling, analytical and overall sampling is given by taking the square root of eqn (1) on both the sides:

s = 6.46 %

h

quartz

explanation: