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Finding the Fourth Proportional to 659.31, 989.19 and 312.61

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Solution

The fourth proportional to 659.31, 989.19 and 312.61 is: 469.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.31 : 989.19 = 312.61 : x
  2. Step 2: Convert to fraction form
    659.31/989.19 = 312.61/x
  3. Step 3: Cross multiply
    659.31x = 989.19 × 312.61
  4. Step 4: Simplify right side
    659.31x = 309,231.17
  5. Step 5: Solve for x
    x = 309,231.17/659.31
  6. Step 6: Final answer
    x = 469.02

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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.