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Finding the Fourth Proportional to 515.44, 711.72 and 398.80

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Solution

The fourth proportional to 515.44, 711.72 and 398.80 is: 550.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.44 : 711.72 = 398.80 : x
  2. Step 2: Convert to fraction form
    515.44/711.72 = 398.80/x
  3. Step 3: Cross multiply
    515.44x = 711.72 × 398.80
  4. Step 4: Simplify right side
    515.44x = 283,833.94
  5. Step 5: Solve for x
    x = 283,833.94/515.44
  6. Step 6: Final answer
    x = 550.66

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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.