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Finding the Fourth Proportional to 643.31, 888.00 and 391.24

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Solution

The fourth proportional to 643.31, 888.00 and 391.24 is: 540.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.31 : 888.00 = 391.24 : x
  2. Step 2: Convert to fraction form
    643.31/888.00 = 391.24/x
  3. Step 3: Cross multiply
    643.31x = 888.00 × 391.24
  4. Step 4: Simplify right side
    643.31x = 347,420.76
  5. Step 5: Solve for x
    x = 347,420.76/643.31
  6. Step 6: Final answer
    x = 540.05

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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.