Home / 3,120.20-4,680.30-811.70

Finding the Fourth Proportional to 3,120.20, 4,680.30 and 811.70

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Solution

The fourth proportional to 3,120.20, 4,680.30 and 811.70 is: 1,217.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,120.20 : 4,680.30 = 811.70 : x
  2. Step 2: Convert to fraction form
    3,120.20/4,680.30 = 811.70/x
  3. Step 3: Cross multiply
    3,120.20x = 4,680.30 × 811.70
  4. Step 4: Simplify right side
    3,120.20x = 3,798,976.11
  5. Step 5: Solve for x
    x = 3,798,976.11/3,120.20
  6. Step 6: Final answer
    x = 1,217.54

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.