Final answer:
To order the set of numbers from least to greatest, convert each number to decimal form, compare the decimals, and convert back to scientific notation if needed.
Step-by-step explanation:
To order the set of numbers from least to greatest:
- Convert each number to its decimal form.
- Compare the decimal forms to determine their order.
- Convert the decimal forms back to scientific notation if necessary.
Based on these steps, the correct order is: 3.1 * 10^-5, 3.6 * 10^-3, 1.1 * 10^4, 1.3 * 10^4.