Final answer:
The U.S. population figure and the conversion of cm to inches are exact, so they have an unlimited number of significant figures. The density of lead has three significant figures, and the conversion of 12 units to dozen is also an exact number with unlimited significant figures. d. 12 = 1 dozen
Step-by-step explanation:
Indicating the number of significant figures for each quantity involves understanding the rules that define how significant figures are counted. Here's how you identify the significant figures for each of the provided examples:
- a. 284,796,887 (2001 U.S. population) - The population number is typically a 'counted' number, so it is considered to have an unlimited number of significant figures.
- b. 2.54cm = 1 in - This is a definition or an exact conversion, so it also has an unlimited number of significant figures.
- c. 11.4 g/cm³ (density of lead) - This measurement has three significant figures.
- d. 12 = 1 dozen - This is a defined number, which makes it exact and therefore has an unlimited number of significant figures.
Significant figures in measurements are important for precision and accuracy in scientific experiments.