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Finding the Fourth Proportional to 640.89, 960.21 and 457.92

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Solution

The fourth proportional to 640.89, 960.21 and 457.92 is: 686.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.89 : 960.21 = 457.92 : x
  2. Step 2: Convert to fraction form
    640.89/960.21 = 457.92/x
  3. Step 3: Cross multiply
    640.89x = 960.21 × 457.92
  4. Step 4: Simplify right side
    640.89x = 439,699.36
  5. Step 5: Solve for x
    x = 439,699.36/640.89
  6. Step 6: Final answer
    x = 686.08

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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.