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Finding the Fourth Proportional to 717.89, 990.56 and 455.78

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Solution

The fourth proportional to 717.89, 990.56 and 455.78 is: 628.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.89 : 990.56 = 455.78 : x
  2. Step 2: Convert to fraction form
    717.89/990.56 = 455.78/x
  3. Step 3: Cross multiply
    717.89x = 990.56 × 455.78
  4. Step 4: Simplify right side
    717.89x = 451,481.05
  5. Step 5: Solve for x
    x = 451,481.05/717.89
  6. Step 6: Final answer
    x = 628.90

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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.