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Finding the Fourth Proportional to 659.50, 989.13 and 428.23

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Solution

The fourth proportional to 659.50, 989.13 and 428.23 is: 642.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.50 : 989.13 = 428.23 : x
  2. Step 2: Convert to fraction form
    659.50/989.13 = 428.23/x
  3. Step 3: Cross multiply
    659.50x = 989.13 × 428.23
  4. Step 4: Simplify right side
    659.50x = 423,575.14
  5. Step 5: Solve for x
    x = 423,575.14/659.50
  6. Step 6: Final answer
    x = 642.27

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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.