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Finding the Fourth Proportional to 643.55, 887.90 and 486.14

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Solution

The fourth proportional to 643.55, 887.90 and 486.14 is: 670.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.55 : 887.90 = 486.14 : x
  2. Step 2: Convert to fraction form
    643.55/887.90 = 486.14/x
  3. Step 3: Cross multiply
    643.55x = 887.90 × 486.14
  4. Step 4: Simplify right side
    643.55x = 431,636.84
  5. Step 5: Solve for x
    x = 431,636.84/643.55
  6. Step 6: Final answer
    x = 670.72

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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.