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Finding the Fourth Proportional to 818.72, 1,129.85 and 487.16

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Solution

The fourth proportional to 818.72, 1,129.85 and 487.16 is: 672.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.72 : 1,129.85 = 487.16 : x
  2. Step 2: Convert to fraction form
    818.72/1,129.85 = 487.16/x
  3. Step 3: Cross multiply
    818.72x = 1,129.85 × 487.16
  4. Step 4: Simplify right side
    818.72x = 550,417.73
  5. Step 5: Solve for x
    x = 550,417.73/818.72
  6. Step 6: Final answer
    x = 672.29

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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.