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Finding the Fourth Proportional to 643.20, 888 and 512.88

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Solution

The fourth proportional to 643.20, 888 and 512.88 is: 708.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.20 : 888 = 512.88 : x
  2. Step 2: Convert to fraction form
    643.20/888 = 512.88/x
  3. Step 3: Cross multiply
    643.20x = 888 × 512.88
  4. Step 4: Simplify right side
    643.20x = 455,437.44
  5. Step 5: Solve for x
    x = 455,437.44/643.20
  6. Step 6: Final answer
    x = 708.08

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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.