Home / 307.90-424.56-209.71

Finding the Fourth Proportional to 307.90, 424.56 and 209.71

Calculator

Solution

The fourth proportional to 307.90, 424.56 and 209.71 is: 289.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    307.90 : 424.56 = 209.71 : x
  2. Step 2: Convert to fraction form
    307.90/424.56 = 209.71/x
  3. Step 3: Cross multiply
    307.90x = 424.56 × 209.71
  4. Step 4: Simplify right side
    307.90x = 89,034.48
  5. Step 5: Solve for x
    x = 89,034.48/307.90
  6. Step 6: Final answer
    x = 289.17

Related Problems

Find fourth proportional to 153.95, 212.28 and 104.86
Half scale
Find fourth proportional to 615.80, 849.12 and 419.42
Double scale
Find fourth proportional to 308.90, 425.94 and 210.71
Similar ratio
Find fourth proportional to 461.85, 636.84 and 314.57
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.