The numbers from least to greatest are:

$-4, \, -\frac{7}{4} \, (-1.75), \, \frac{1}{2} \, (0.5), \, \sqrt{8} \, (2.83), \, 3.5$

Would you like further details or have any questions?

Here are 5 related questions:

1. How do you compare fractions with decimals?
2. What is the approximate value of $\sqrt{8}$ in decimal form?
3. How would you order a mix of positive and negative numbers?
4. What other methods can be used to order a set of numbers?
5. Can square roots always be represented as decimals?

Tip: When comparing fractions and square roots, it's often easier to convert them to decimal form first for clarity.