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Finding the Fourth Proportional to 660.38, 990.56 and 388.20

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Solution

The fourth proportional to 660.38, 990.56 and 388.20 is: 582.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.38 : 990.56 = 388.20 : x
  2. Step 2: Convert to fraction form
    660.38/990.56 = 388.20/x
  3. Step 3: Cross multiply
    660.38x = 990.56 × 388.20
  4. Step 4: Simplify right side
    660.38x = 384,535.39
  5. Step 5: Solve for x
    x = 384,535.39/660.38
  6. Step 6: Final answer
    x = 582.29

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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.