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Finding the Fourth Proportional to 781.69, 1,178.54 and 728.82

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Solution

The fourth proportional to 781.69, 1,178.54 and 728.82 is: 1,098.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.69 : 1,178.54 = 728.82 : x
  2. Step 2: Convert to fraction form
    781.69/1,178.54 = 728.82/x
  3. Step 3: Cross multiply
    781.69x = 1,178.54 × 728.82
  4. Step 4: Simplify right side
    781.69x = 858,943.52
  5. Step 5: Solve for x
    x = 858,943.52/781.69
  6. Step 6: Final answer
    x = 1,098.83

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.