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Finding the Fourth Proportional to 709.79, 979.97 and 660.78

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Solution

The fourth proportional to 709.79, 979.97 and 660.78 is: 912.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.79 : 979.97 = 660.78 : x
  2. Step 2: Convert to fraction form
    709.79/979.97 = 660.78/x
  3. Step 3: Cross multiply
    709.79x = 979.97 × 660.78
  4. Step 4: Simplify right side
    709.79x = 647,541.27
  5. Step 5: Solve for x
    x = 647,541.27/709.79
  6. Step 6: Final answer
    x = 912.31

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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.