To compare the two numbers, we need to compare the ratio of 1.9 • 10^-8 to 4.2 • 10^-13.
The first number, 1.9 • 10^-8, can be written as 0.00000019.
The second number, 4.2 • 10^-13, can be written as 0.000000000000042.
We can see that 1.9 • 10^-8 is much larger than 4.2 • 10^-13, as it has more trailing zeros. We can estimate that 1.9 • 10^-8 is about 45 times larger than 4.2 • 10^-13.
We can confirm this by counting the difference in the number of trailing zeros in both numbers. 1.910^-8 has 8 trailing zeroes and 4.210^-13 has 13 trailing zeroes, meaning 1.910^-8 is 8-13= -5 orders of magnitude larger than 4.210^-13