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Finding the Fourth Proportional to 640.55, 958.80 and 458.30

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Solution

The fourth proportional to 640.55, 958.80 and 458.30 is: 686.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.55 : 958.80 = 458.30 : x
  2. Step 2: Convert to fraction form
    640.55/958.80 = 458.30/x
  3. Step 3: Cross multiply
    640.55x = 958.80 × 458.30
  4. Step 4: Simplify right side
    640.55x = 439,418.04
  5. Step 5: Solve for x
    x = 439,418.04/640.55
  6. Step 6: Final answer
    x = 686.00

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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.