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Finding the Fourth Proportional to 686.47, 1,029.86 and 253.63

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Solution

The fourth proportional to 686.47, 1,029.86 and 253.63 is: 380.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.47 : 1,029.86 = 253.63 : x
  2. Step 2: Convert to fraction form
    686.47/1,029.86 = 253.63/x
  3. Step 3: Cross multiply
    686.47x = 1,029.86 × 253.63
  4. Step 4: Simplify right side
    686.47x = 261,196.97
  5. Step 5: Solve for x
    x = 261,196.97/686.47
  6. Step 6: Final answer
    x = 380.49

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Double scale
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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.