Home / 312.30-431.04-212.85

Finding the Fourth Proportional to 312.30, 431.04 and 212.85

Calculator

Solution

The fourth proportional to 312.30, 431.04 and 212.85 is: 293.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.30 : 431.04 = 212.85 : x
  2. Step 2: Convert to fraction form
    312.30/431.04 = 212.85/x
  3. Step 3: Cross multiply
    312.30x = 431.04 × 212.85
  4. Step 4: Simplify right side
    312.30x = 91,746.86
  5. Step 5: Solve for x
    x = 91,746.86/312.30
  6. Step 6: Final answer
    x = 293.78

Related Problems

Find fourth proportional to 156.15, 215.52 and 106.43
Half scale
Find fourth proportional to 624.60, 862.08 and 425.70
Double scale
Find fourth proportional to 313.30, 432.42 and 213.85
Similar ratio
Find fourth proportional to 468.45, 646.56 and 319.28
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.