What is the mean concentration of nickel from the provided daily composite samples?

To determine the mean concentration of nickel from the daily composite samples, you first need to sum up all the individual concentrations obtained from the samples and then divide that total by the number of samples.

In this case, the correct answer being 8.4 mg/L indicates that when the concentrations of nickel from all composite samples were added together and then divided by the number of samples, the resulting average or mean concentration was found to be 8.4 mg/L. This process ensures that the calculation reflects a true average concentration present in the samples, taking into account the variations in concentrations across different days.

The mean is a crucial metric in environmental compliance as it provides insights into the overall presence of contaminants like nickel over a specified period, which is vital for assessing compliance with environmental regulations and determining any necessary remediation or prevention strategies. This calculation is fundamental for inspectors monitoring water quality or other environmental samples to ensure they meet safety guidelines and standards.