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Finding the Fourth Proportional to 840.29, 1,260.59 and 687.60

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Solution

The fourth proportional to 840.29, 1,260.59 and 687.60 is: 1,031.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.29 : 1,260.59 = 687.60 : x
  2. Step 2: Convert to fraction form
    840.29/1,260.59 = 687.60/x
  3. Step 3: Cross multiply
    840.29x = 1,260.59 × 687.60
  4. Step 4: Simplify right side
    840.29x = 866,778.25
  5. Step 5: Solve for x
    x = 866,778.25/840.29
  6. Step 6: Final answer
    x = 1,031.53

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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.