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Finding the Fourth Proportional to 840.57, 1,260.21 and 515.55

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Solution

The fourth proportional to 840.57, 1,260.21 and 515.55 is: 772.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.57 : 1,260.21 = 515.55 : x
  2. Step 2: Convert to fraction form
    840.57/1,260.21 = 515.55/x
  3. Step 3: Cross multiply
    840.57x = 1,260.21 × 515.55
  4. Step 4: Simplify right side
    840.57x = 649,701.27
  5. Step 5: Solve for x
    x = 649,701.27/840.57
  6. Step 6: Final answer
    x = 772.93

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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.