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Finding the Fourth Proportional to 659.08, 988.14 and 428.20

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Solution

The fourth proportional to 659.08, 988.14 and 428.20 is: 641.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.08 : 988.14 = 428.20 : x
  2. Step 2: Convert to fraction form
    659.08/988.14 = 428.20/x
  3. Step 3: Cross multiply
    659.08x = 988.14 × 428.20
  4. Step 4: Simplify right side
    659.08x = 423,121.55
  5. Step 5: Solve for x
    x = 423,121.55/659.08
  6. Step 6: Final answer
    x = 641.99

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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.