need help to see if my work it correct in sig fig to double check please and thank you

Question

5. You will be given some samples to weigh on the electronic balance in the laboratory. Place a piece of weighing paper on the pan of the balance and push the zero (tare) button so the balance registers 0.000 g. Carefully place one of the samples on the paper and record its mass in table below. Carefully remove the sample. Repeat this procedure for the other samples. Determine the average mass and average deviation of the samples. Show all work. Record the individual masses of each item in the blanks to the left below.

Sample                       Mass                           Average Mass ____________            g

No.

1                     __5.029_____            Average Deviation ____________ g

2                     __5.010_____            Standard Deviation ____________ g

3                     __4.983_____

4                     __5.036_____

5                     __4.989______

Answer 1

Hi Christina

You want to record each of the masses exactly as they were on the scale- good work with that.

Now when you take the average, add all of the numbers together.

For adding sig figs, you use the largest/least specific decimal as your limit. So you may keep all the numbers to 3 numbers after the decimal (thousandths). Adding and subtracting both work with way.

Now you can divide to find the average. You are going to divide by 5 since there are 5 numbers. For dividing you want to take the number of sig figs for the term that has the least sig figs. Multiplying works the same way (exponents and roots count as multiplication/division for this purpose)

Just one thing- averages are a bit weird. The 5 is a constant its not a data point for sig figs, thus you can divide by 5 and go with the number of sig figs from just the sum (for your case 4). You get 5.0094 and can answer 5.009 accounting for significant figures.

Keep the same pattern going for the last 2 calculations as well!

Please reach out if you need additional help!