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Finding the Fourth Proportional to 717.53, 990.15 and 422.78

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Solution

The fourth proportional to 717.53, 990.15 and 422.78 is: 583.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.53 : 990.15 = 422.78 : x
  2. Step 2: Convert to fraction form
    717.53/990.15 = 422.78/x
  3. Step 3: Cross multiply
    717.53x = 990.15 × 422.78
  4. Step 4: Simplify right side
    717.53x = 418,615.62
  5. Step 5: Solve for x
    x = 418,615.62/717.53
  6. Step 6: Final answer
    x = 583.41

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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.