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Finding the Fourth Proportional to 660.75, 990.81 and 313.87

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Solution

The fourth proportional to 660.75, 990.81 and 313.87 is: 470.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.75 : 990.81 = 313.87 : x
  2. Step 2: Convert to fraction form
    660.75/990.81 = 313.87/x
  3. Step 3: Cross multiply
    660.75x = 990.81 × 313.87
  4. Step 4: Simplify right side
    660.75x = 310,983.97
  5. Step 5: Solve for x
    x = 310,983.97/660.75
  6. Step 6: Final answer
    x = 470.65

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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.