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Finding the Fourth Proportional to 660.84, 991.20 and 445.80

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Solution

The fourth proportional to 660.84, 991.20 and 445.80 is: 668.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.84 : 991.20 = 445.80 : x
  2. Step 2: Convert to fraction form
    660.84/991.20 = 445.80/x
  3. Step 3: Cross multiply
    660.84x = 991.20 × 445.80
  4. Step 4: Simplify right side
    660.84x = 441,876.96
  5. Step 5: Solve for x
    x = 441,876.96/660.84
  6. Step 6: Final answer
    x = 668.66

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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.