What are some sources of error that can occur in a measurement lab involving mass and volume?

Psycoloshist albert bandits developed a theory of

How much hazardous chemical waste is produced per year in the us? a) 25 million metric tons b) 100 million metric tons c) 250 million metric tons d) 700 million metric tons e) 950 million metric tons

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1. which statement is true if we are testing the null hypothesis at the 95% confidence level? a. the difference of the two means is significant, so the null hypothesis must be rejected. b. the difference of the two means is significant, so the null hypothesis must be accepted. c. the difference of the two means is not significant, so the null hypothesis must be rejected. d. the difference of the two means is not significant, so the null hypothesis must be accepted.