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Finding the Fourth Proportional to 522.80, 781.02 and 394.80

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Solution

The fourth proportional to 522.80, 781.02 and 394.80 is: 589.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    522.80 : 781.02 = 394.80 : x
  2. Step 2: Convert to fraction form
    522.80/781.02 = 394.80/x
  3. Step 3: Cross multiply
    522.80x = 781.02 × 394.80
  4. Step 4: Simplify right side
    522.80x = 308,346.70
  5. Step 5: Solve for x
    x = 308,346.70/522.80
  6. Step 6: Final answer
    x = 589.80

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.