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Finding the Fourth Proportional to 840.54, 1,260.80 and 515.26

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Solution

The fourth proportional to 840.54, 1,260.80 and 515.26 is: 772.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.54 : 1,260.80 = 515.26 : x
  2. Step 2: Convert to fraction form
    840.54/1,260.80 = 515.26/x
  3. Step 3: Cross multiply
    840.54x = 1,260.80 × 515.26
  4. Step 4: Simplify right side
    840.54x = 649,639.81
  5. Step 5: Solve for x
    x = 649,639.81/840.54
  6. Step 6: Final answer
    x = 772.88

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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.