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Finding the Fourth Proportional to 709.40, 979.59 and 686.16

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Solution

The fourth proportional to 709.40, 979.59 and 686.16 is: 947.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.40 : 979.59 = 686.16 : x
  2. Step 2: Convert to fraction form
    709.40/979.59 = 686.16/x
  3. Step 3: Cross multiply
    709.40x = 979.59 × 686.16
  4. Step 4: Simplify right side
    709.40x = 672,160.80
  5. Step 5: Solve for x
    x = 672,160.80/709.40
  6. Step 6: Final answer
    x = 947.51

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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.