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Finding the Fourth Proportional to 766.86, 1,149.78 and 279.90

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Solution

The fourth proportional to 766.86, 1,149.78 and 279.90 is: 419.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    766.86 : 1,149.78 = 279.90 : x
  2. Step 2: Convert to fraction form
    766.86/1,149.78 = 279.90/x
  3. Step 3: Cross multiply
    766.86x = 1,149.78 × 279.90
  4. Step 4: Simplify right side
    766.86x = 321,823.42
  5. Step 5: Solve for x
    x = 321,823.42/766.86
  6. Step 6: Final answer
    x = 419.66

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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.