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Finding the Fourth Proportional to 766.74, 1,150.78 and 420.39

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Solution

The fourth proportional to 766.74, 1,150.78 and 420.39 is: 630.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    766.74 : 1,150.78 = 420.39 : x
  2. Step 2: Convert to fraction form
    766.74/1,150.78 = 420.39/x
  3. Step 3: Cross multiply
    766.74x = 1,150.78 × 420.39
  4. Step 4: Simplify right side
    766.74x = 483,776.40
  5. Step 5: Solve for x
    x = 483,776.40/766.74
  6. Step 6: Final answer
    x = 630.95

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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.