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Finding the Fourth Proportional to 681.20, 939.60 and 418.88

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Solution

The fourth proportional to 681.20, 939.60 and 418.88 is: 577.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.20 : 939.60 = 418.88 : x
  2. Step 2: Convert to fraction form
    681.20/939.60 = 418.88/x
  3. Step 3: Cross multiply
    681.20x = 939.60 × 418.88
  4. Step 4: Simplify right side
    681.20x = 393,579.65
  5. Step 5: Solve for x
    x = 393,579.65/681.20
  6. Step 6: Final answer
    x = 577.77

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.