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Finding the Fourth Proportional to 842.32, 1,263.78 and 409.78

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Solution

The fourth proportional to 842.32, 1,263.78 and 409.78 is: 614.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.32 : 1,263.78 = 409.78 : x
  2. Step 2: Convert to fraction form
    842.32/1,263.78 = 409.78/x
  3. Step 3: Cross multiply
    842.32x = 1,263.78 × 409.78
  4. Step 4: Simplify right side
    842.32x = 517,871.77
  5. Step 5: Solve for x
    x = 517,871.77/842.32
  6. Step 6: Final answer
    x = 614.82

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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.