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Finding the Fourth Proportional to 687.80, 948.66 and 438.92

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Solution

The fourth proportional to 687.80, 948.66 and 438.92 is: 605.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.80 : 948.66 = 438.92 : x
  2. Step 2: Convert to fraction form
    687.80/948.66 = 438.92/x
  3. Step 3: Cross multiply
    687.80x = 948.66 × 438.92
  4. Step 4: Simplify right side
    687.80x = 416,385.85
  5. Step 5: Solve for x
    x = 416,385.85/687.80
  6. Step 6: Final answer
    x = 605.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.