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Finding the Fourth Proportional to 659.40, 987.90 and 556.20

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Solution

The fourth proportional to 659.40, 987.90 and 556.20 is: 833.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.40 : 987.90 = 556.20 : x
  2. Step 2: Convert to fraction form
    659.40/987.90 = 556.20/x
  3. Step 3: Cross multiply
    659.40x = 987.90 × 556.20
  4. Step 4: Simplify right side
    659.40x = 549,469.98
  5. Step 5: Solve for x
    x = 549,469.98/659.40
  6. Step 6: Final answer
    x = 833.29

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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.