Final answer:
The fractions 9/12, 3/10, 1/6, and 1/8 in descending order are 9/12 (3/4), 3/10, 1/6, and 1/8 as they correspond to the decimal values 0.75, 0.3, approximately 0.1667, and 0.125 respectively.
Step-by-step explanation:
To order the fractions 3/10, 9/12, 1/6, 1/8 from largest to smallest, we can start by converting them to have a common denominator or by converting them to decimal form to compare directly. The fraction 9/12 can be simplified to 3/4 which is equivalent to 0.75 when converted to a decimal. The fraction 3/10 is equivalent to 0.3 as a decimal. For the fraction 1/6, converting it to a decimal gives us approximately 0.1667. The fraction 1/8 as a decimal is equal to 0.125. Now we can easily see the order from largest to smallest is 9/12 (3/4), 3/10, 1/6, and then 1/8.