#### Answer

$\frac{1}{16}$ or $.0625$

#### Work Step by Step

To find the difference, you must make the two numbers in like format.
To find the fraction, you find that 1.5 is equal to $1\frac{8}{16}$. Therefore, $1\frac{9}{16}-1\frac{8}{16}=\frac{1}{16}$
Now that you know the difference is $\frac{1}{16}$, you can convert to decimal form which is $.0625$.