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Finding the Fourth Proportional to 645.78, 891.17 and 351.05

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Solution

The fourth proportional to 645.78, 891.17 and 351.05 is: 484.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.78 : 891.17 = 351.05 : x
  2. Step 2: Convert to fraction form
    645.78/891.17 = 351.05/x
  3. Step 3: Cross multiply
    645.78x = 891.17 × 351.05
  4. Step 4: Simplify right side
    645.78x = 312,841.65
  5. Step 5: Solve for x
    x = 312,841.65/645.78
  6. Step 6: Final answer
    x = 484.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.