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Finding the Fourth Proportional to 689.97, 1,035 and 257.13

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Solution

The fourth proportional to 689.97, 1,035 and 257.13 is: 385.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.97 : 1,035 = 257.13 : x
  2. Step 2: Convert to fraction form
    689.97/1,035 = 257.13/x
  3. Step 3: Cross multiply
    689.97x = 1,035 × 257.13
  4. Step 4: Simplify right side
    689.97x = 266,129.55
  5. Step 5: Solve for x
    x = 266,129.55/689.97
  6. Step 6: Final answer
    x = 385.71

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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.