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Finding the Fourth Proportional to 711.72, 981.72 and 687.96

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Solution

The fourth proportional to 711.72, 981.72 and 687.96 is: 948.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.72 : 981.72 = 687.96 : x
  2. Step 2: Convert to fraction form
    711.72/981.72 = 687.96/x
  3. Step 3: Cross multiply
    711.72x = 981.72 × 687.96
  4. Step 4: Simplify right side
    711.72x = 675,384.09
  5. Step 5: Solve for x
    x = 675,384.09/711.72
  6. Step 6: Final answer
    x = 948.95

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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.