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Finding the Fourth Proportional to 661.44, 990.87 and 314.28

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Solution

The fourth proportional to 661.44, 990.87 and 314.28 is: 470.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.44 : 990.87 = 314.28 : x
  2. Step 2: Convert to fraction form
    661.44/990.87 = 314.28/x
  3. Step 3: Cross multiply
    661.44x = 990.87 × 314.28
  4. Step 4: Simplify right side
    661.44x = 311,410.62
  5. Step 5: Solve for x
    x = 311,410.62/661.44
  6. Step 6: Final answer
    x = 470.81

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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.