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Finding the Fourth Proportional to 778.92, 1,073.87 and 645.63

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Solution

The fourth proportional to 778.92, 1,073.87 and 645.63 is: 890.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.92 : 1,073.87 = 645.63 : x
  2. Step 2: Convert to fraction form
    778.92/1,073.87 = 645.63/x
  3. Step 3: Cross multiply
    778.92x = 1,073.87 × 645.63
  4. Step 4: Simplify right side
    778.92x = 693,319.46
  5. Step 5: Solve for x
    x = 693,319.46/778.92
  6. Step 6: Final answer
    x = 890.10

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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.