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Finding the Fourth Proportional to 778.15, 1,166.55 and 387.91

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Solution

The fourth proportional to 778.15, 1,166.55 and 387.91 is: 581.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.15 : 1,166.55 = 387.91 : x
  2. Step 2: Convert to fraction form
    778.15/1,166.55 = 387.91/x
  3. Step 3: Cross multiply
    778.15x = 1,166.55 × 387.91
  4. Step 4: Simplify right side
    778.15x = 452,516.41
  5. Step 5: Solve for x
    x = 452,516.41/778.15
  6. Step 6: Final answer
    x = 581.53

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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.