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Finding the Fourth Proportional to 717.85, 990.39 and 422.91

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Solution

The fourth proportional to 717.85, 990.39 and 422.91 is: 583.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.85 : 990.39 = 422.91 : x
  2. Step 2: Convert to fraction form
    717.85/990.39 = 422.91/x
  3. Step 3: Cross multiply
    717.85x = 990.39 × 422.91
  4. Step 4: Simplify right side
    717.85x = 418,845.83
  5. Step 5: Solve for x
    x = 418,845.83/717.85
  6. Step 6: Final answer
    x = 583.47

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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.