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Finding the Fourth Proportional to 711.28, 981.60 and 400.72

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Solution

The fourth proportional to 711.28, 981.60 and 400.72 is: 553.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.28 : 981.60 = 400.72 : x
  2. Step 2: Convert to fraction form
    711.28/981.60 = 400.72/x
  3. Step 3: Cross multiply
    711.28x = 981.60 × 400.72
  4. Step 4: Simplify right side
    711.28x = 393,346.75
  5. Step 5: Solve for x
    x = 393,346.75/711.28
  6. Step 6: Final answer
    x = 553.01

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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.