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Finding the Fourth Proportional to 689.60, 1,034.87 and 257.12

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Solution

The fourth proportional to 689.60, 1,034.87 and 257.12 is: 385.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.60 : 1,034.87 = 257.12 : x
  2. Step 2: Convert to fraction form
    689.60/1,034.87 = 257.12/x
  3. Step 3: Cross multiply
    689.60x = 1,034.87 × 257.12
  4. Step 4: Simplify right side
    689.60x = 266,079.31
  5. Step 5: Solve for x
    x = 266,079.31/689.60
  6. Step 6: Final answer
    x = 385.85

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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.