A watch manufacturer claims that its watches gain or lose no more than 9 seconds in a year. How accurate are these watches, expressed as a percentage?

Write the following numbers in powers of 10 notation:

(e) 0.219

Write out the following numbers in full with the correct number of zeros:

(c) 2.5 x 10⁻¹

Time intervals measured with a physical stopwatch typically have an uncertainty of about 0.2 s, due to human reaction time at the start and stop moments. What is the percent uncertainty of a hand-timed measurement of 4.5 min?

Write the following as full (decimal) numbers without prefixes on the units:

(e) 22.5 nm

Express the following using the prefixes of Table 1–4: 18 x 10² bucks and