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Finding the Fourth Proportional to 711.97, 981.78 and 487.67

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Solution

The fourth proportional to 711.97, 981.78 and 487.67 is: 672.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.97 : 981.78 = 487.67 : x
  2. Step 2: Convert to fraction form
    711.97/981.78 = 487.67/x
  3. Step 3: Cross multiply
    711.97x = 981.78 × 487.67
  4. Step 4: Simplify right side
    711.97x = 478,779.74
  5. Step 5: Solve for x
    x = 478,779.74/711.97
  6. Step 6: Final answer
    x = 672.48

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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.