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Finding the Fourth Proportional to 838.60, 1,257.90 and 619.90

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Solution

The fourth proportional to 838.60, 1,257.90 and 619.90 is: 929.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.60 : 1,257.90 = 619.90 : x
  2. Step 2: Convert to fraction form
    838.60/1,257.90 = 619.90/x
  3. Step 3: Cross multiply
    838.60x = 1,257.90 × 619.90
  4. Step 4: Simplify right side
    838.60x = 779,772.21
  5. Step 5: Solve for x
    x = 779,772.21/838.60
  6. Step 6: Final answer
    x = 929.85

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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.