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Finding the Fourth Proportional to 659.90, 988.89 and 412.98

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Solution

The fourth proportional to 659.90, 988.89 and 412.98 is: 618.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.90 : 988.89 = 412.98 : x
  2. Step 2: Convert to fraction form
    659.90/988.89 = 412.98/x
  3. Step 3: Cross multiply
    659.90x = 988.89 × 412.98
  4. Step 4: Simplify right side
    659.90x = 408,391.79
  5. Step 5: Solve for x
    x = 408,391.79/659.90
  6. Step 6: Final answer
    x = 618.87

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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.