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Finding the Fourth Proportional to 778.40, 1,074.14 and 557.72

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Solution

The fourth proportional to 778.40, 1,074.14 and 557.72 is: 769.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.40 : 1,074.14 = 557.72 : x
  2. Step 2: Convert to fraction form
    778.40/1,074.14 = 557.72/x
  3. Step 3: Cross multiply
    778.40x = 1,074.14 × 557.72
  4. Step 4: Simplify right side
    778.40x = 599,066.57
  5. Step 5: Solve for x
    x = 599,066.57/778.40
  6. Step 6: Final answer
    x = 769.61

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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.