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Finding the Fourth Proportional to 781.08, 1,163 and 769.40

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Solution

The fourth proportional to 781.08, 1,163 and 769.40 is: 1,145.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.08 : 1,163 = 769.40 : x
  2. Step 2: Convert to fraction form
    781.08/1,163 = 769.40/x
  3. Step 3: Cross multiply
    781.08x = 1,163 × 769.40
  4. Step 4: Simplify right side
    781.08x = 894,812.20
  5. Step 5: Solve for x
    x = 894,812.20/781.08
  6. Step 6: Final answer
    x = 1,145.61

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.