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Finding the Fourth Proportional to 660.40, 911.68 and 411.86

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Solution

The fourth proportional to 660.40, 911.68 and 411.86 is: 568.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.40 : 911.68 = 411.86 : x
  2. Step 2: Convert to fraction form
    660.40/911.68 = 411.86/x
  3. Step 3: Cross multiply
    660.40x = 911.68 × 411.86
  4. Step 4: Simplify right side
    660.40x = 375,480.18
  5. Step 5: Solve for x
    x = 375,480.18/660.40
  6. Step 6: Final answer
    x = 568.56

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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.