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Finding the Fourth Proportional to 640.21, 958.43 and 486.75

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Solution

The fourth proportional to 640.21, 958.43 and 486.75 is: 728.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.21 : 958.43 = 486.75 : x
  2. Step 2: Convert to fraction form
    640.21/958.43 = 486.75/x
  3. Step 3: Cross multiply
    640.21x = 958.43 × 486.75
  4. Step 4: Simplify right side
    640.21x = 466,511.01
  5. Step 5: Solve for x
    x = 466,511.01/640.21
  6. Step 6: Final answer
    x = 728.69

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.