What is the median of the data in table 2

What would the measurement of this feature be?

My son is planning to build a lego plan for a school project and he wants to estimate how much it will weigh. He measured a single lego to weight 12.1 grams. His plan will consist of 100 equally sized legos plus 3 legos that are a quarter of the size for a total of 100.75. He calculates the total mass as 1,219.075 grams. If my son understood significant figures what would his measurement be?

When recording measurements with long numbers

My son is planning to build a lego plan for a school project and he wants to estimate how much it will weigh. He measured a single lego to weight 12.1 grams. His plan will consist of 100 equally sized legos plus 3 legos that are a quarter of the size for a total of 100.75. He calculates the total mass as 1,219.075 grams. If my son understood significant figures what would his measurement be?

What would the measurement of this feature be?

When recording measurements with long numbers

Approximately, what is the standard deviation of the data in table 2

NIST

Identify the number of significant figures for 1.001