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Finding the Fourth Proportional to 660.96, 911.86 and 399.13

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Solution

The fourth proportional to 660.96, 911.86 and 399.13 is: 550.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.96 : 911.86 = 399.13 : x
  2. Step 2: Convert to fraction form
    660.96/911.86 = 399.13/x
  3. Step 3: Cross multiply
    660.96x = 911.86 × 399.13
  4. Step 4: Simplify right side
    660.96x = 363,947.40
  5. Step 5: Solve for x
    x = 363,947.40/660.96
  6. Step 6: Final answer
    x = 550.63

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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.