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Finding the Fourth Proportional to 643.13, 886.70 and 511.91

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Solution

The fourth proportional to 643.13, 886.70 and 511.91 is: 705.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.13 : 886.70 = 511.91 : x
  2. Step 2: Convert to fraction form
    643.13/886.70 = 511.91/x
  3. Step 3: Cross multiply
    643.13x = 886.70 × 511.91
  4. Step 4: Simplify right side
    643.13x = 453,910.60
  5. Step 5: Solve for x
    x = 453,910.60/643.13
  6. Step 6: Final answer
    x = 705.78

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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.