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Finding the Fourth Proportional to 840.88, 1,259.70 and 686.98

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Solution

The fourth proportional to 840.88, 1,259.70 and 686.98 is: 1,029.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.88 : 1,259.70 = 686.98 : x
  2. Step 2: Convert to fraction form
    840.88/1,259.70 = 686.98/x
  3. Step 3: Cross multiply
    840.88x = 1,259.70 × 686.98
  4. Step 4: Simplify right side
    840.88x = 865,388.71
  5. Step 5: Solve for x
    x = 865,388.71/840.88
  6. Step 6: Final answer
    x = 1,029.15

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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.