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Finding the Fourth Proportional to 643.50, 887.49 and 486.72

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Solution

The fourth proportional to 643.50, 887.49 and 486.72 is: 671.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.50 : 887.49 = 486.72 : x
  2. Step 2: Convert to fraction form
    643.50/887.49 = 486.72/x
  3. Step 3: Cross multiply
    643.50x = 887.49 × 486.72
  4. Step 4: Simplify right side
    643.50x = 431,959.13
  5. Step 5: Solve for x
    x = 431,959.13/643.50
  6. Step 6: Final answer
    x = 671.27

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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.