Time weighted average example

1. How do you calculate a time-weighted average?
2. What is an 8 hour time-weighted average?
3. What is an example of a weighted average?
4. What is time-weighted average used for?

How do you calculate a time-weighted average?

A time-weighted average is equal to the sum of the portion of each time period (as a decimal, such as 0.25 hour) multiplied by the levels of the substance or agent during the time period divided by the hours in the workday (usually 8 hours).

What is an 8 hour time-weighted average?

"TWA is the employee's average airborne exposure in any 8-hour work shift of a 40-hour work week which shall not be exceeded." The 8-hour TWA PEL is the level of exposure established as the highest level of exposure an employee may be exposed to without incurring the risk of adverse health effects.

What is an example of a weighted average?

For example, say an investor acquires 100 shares of a company in year one at $10, and 50 shares of the same stock in year two at $40. To get a weighted average of the price paid, the investor multiplies 100 shares by $10 for year one and 50 shares by $40 for year two, then adds the results to get a total of $3,000.

What is time-weighted average used for?

The TWA for the exposure to a chemical can be used when both the chemical concentration and time for exposure varies over time. It is thus used as the average exposure to a contaminant to which workers may be exposed without adverse effect over a period such as in an 8-hour day or 40-hour week (an average work shift).