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Finding the Fourth Proportional to 687.08, 947.71 and 438.71

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Solution

The fourth proportional to 687.08, 947.71 and 438.71 is: 605.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.08 : 947.71 = 438.71 : x
  2. Step 2: Convert to fraction form
    687.08/947.71 = 438.71/x
  3. Step 3: Cross multiply
    687.08x = 947.71 × 438.71
  4. Step 4: Simplify right side
    687.08x = 415,764.02
  5. Step 5: Solve for x
    x = 415,764.02/687.08
  6. Step 6: Final answer
    x = 605.12

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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.