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Finding the Fourth Proportional to 660.80, 911.92 and 381.05

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Solution

The fourth proportional to 660.80, 911.92 and 381.05 is: 525.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.80 : 911.92 = 381.05 : x
  2. Step 2: Convert to fraction form
    660.80/911.92 = 381.05/x
  3. Step 3: Cross multiply
    660.80x = 911.92 × 381.05
  4. Step 4: Simplify right side
    660.80x = 347,487.12
  5. Step 5: Solve for x
    x = 347,487.12/660.80
  6. Step 6: Final answer
    x = 525.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.