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Finding the Fourth Proportional to 643.10, 886.86 and 518.69

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Solution

The fourth proportional to 643.10, 886.86 and 518.69 is: 715.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.10 : 886.86 = 518.69 : x
  2. Step 2: Convert to fraction form
    643.10/886.86 = 518.69/x
  3. Step 3: Cross multiply
    643.10x = 886.86 × 518.69
  4. Step 4: Simplify right side
    643.10x = 460,000.98
  5. Step 5: Solve for x
    x = 460,000.98/643.10
  6. Step 6: Final answer
    x = 715.29

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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.