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Finding the Fourth Proportional to 840.20, 1,251.64 and 814.72

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Solution

The fourth proportional to 840.20, 1,251.64 and 814.72 is: 1,213.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.20 : 1,251.64 = 814.72 : x
  2. Step 2: Convert to fraction form
    840.20/1,251.64 = 814.72/x
  3. Step 3: Cross multiply
    840.20x = 1,251.64 × 814.72
  4. Step 4: Simplify right side
    840.20x = 1,019,736.14
  5. Step 5: Solve for x
    x = 1,019,736.14/840.20
  6. Step 6: Final answer
    x = 1,213.68

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.