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Finding the Fourth Proportional to 709.80, 979.28 and 447.76

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Solution

The fourth proportional to 709.80, 979.28 and 447.76 is: 617.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.80 : 979.28 = 447.76 : x
  2. Step 2: Convert to fraction form
    709.80/979.28 = 447.76/x
  3. Step 3: Cross multiply
    709.80x = 979.28 × 447.76
  4. Step 4: Simplify right side
    709.80x = 438,482.41
  5. Step 5: Solve for x
    x = 438,482.41/709.80
  6. Step 6: Final answer
    x = 617.75

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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.