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Finding the Fourth Proportional to 660.12, 990.12 and 289.92

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Solution

The fourth proportional to 660.12, 990.12 and 289.92 is: 434.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.12 : 990.12 = 289.92 : x
  2. Step 2: Convert to fraction form
    660.12/990.12 = 289.92/x
  3. Step 3: Cross multiply
    660.12x = 990.12 × 289.92
  4. Step 4: Simplify right side
    660.12x = 287,055.59
  5. Step 5: Solve for x
    x = 287,055.59/660.12
  6. Step 6: Final answer
    x = 434.85

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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.