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Finding the Fourth Proportional to 768.12, 1,150.80 and 421.08

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Solution

The fourth proportional to 768.12, 1,150.80 and 421.08 is: 630.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.12 : 1,150.80 = 421.08 : x
  2. Step 2: Convert to fraction form
    768.12/1,150.80 = 421.08/x
  3. Step 3: Cross multiply
    768.12x = 1,150.80 × 421.08
  4. Step 4: Simplify right side
    768.12x = 484,578.86
  5. Step 5: Solve for x
    x = 484,578.86/768.12
  6. Step 6: Final answer
    x = 630.86

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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.