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Finding the Fourth Proportional to 660.24, 990.36 and 318.48

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Solution

The fourth proportional to 660.24, 990.36 and 318.48 is: 477.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.24 : 990.36 = 318.48 : x
  2. Step 2: Convert to fraction form
    660.24/990.36 = 318.48/x
  3. Step 3: Cross multiply
    660.24x = 990.36 × 318.48
  4. Step 4: Simplify right side
    660.24x = 315,409.85
  5. Step 5: Solve for x
    x = 315,409.85/660.24
  6. Step 6: Final answer
    x = 477.72

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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.