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Finding the Fourth Proportional to 659.56, 989.34 and 312.90

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Solution

The fourth proportional to 659.56, 989.34 and 312.90 is: 469.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.56 : 989.34 = 312.90 : x
  2. Step 2: Convert to fraction form
    659.56/989.34 = 312.90/x
  3. Step 3: Cross multiply
    659.56x = 989.34 × 312.90
  4. Step 4: Simplify right side
    659.56x = 309,564.49
  5. Step 5: Solve for x
    x = 309,564.49/659.56
  6. Step 6: Final answer
    x = 469.35

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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.