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Finding the Fourth Proportional to 660.85, 990.96 and 387.02

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Solution

The fourth proportional to 660.85, 990.96 and 387.02 is: 580.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.85 : 990.96 = 387.02 : x
  2. Step 2: Convert to fraction form
    660.85/990.96 = 387.02/x
  3. Step 3: Cross multiply
    660.85x = 990.96 × 387.02
  4. Step 4: Simplify right side
    660.85x = 383,521.34
  5. Step 5: Solve for x
    x = 383,521.34/660.85
  6. Step 6: Final answer
    x = 580.35

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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.