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Finding the Fourth Proportional to 786.72, 1,178.97 and 539.70

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Solution

The fourth proportional to 786.72, 1,178.97 and 539.70 is: 808.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.72 : 1,178.97 = 539.70 : x
  2. Step 2: Convert to fraction form
    786.72/1,178.97 = 539.70/x
  3. Step 3: Cross multiply
    786.72x = 1,178.97 × 539.70
  4. Step 4: Simplify right side
    786.72x = 636,290.11
  5. Step 5: Solve for x
    x = 636,290.11/786.72
  6. Step 6: Final answer
    x = 808.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.