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Finding the Fourth Proportional to 398.70, 550.80 and 315.54

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Solution

The fourth proportional to 398.70, 550.80 and 315.54 is: 435.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.70 : 550.80 = 315.54 : x
  2. Step 2: Convert to fraction form
    398.70/550.80 = 315.54/x
  3. Step 3: Cross multiply
    398.70x = 550.80 × 315.54
  4. Step 4: Simplify right side
    398.70x = 173,799.43
  5. Step 5: Solve for x
    x = 173,799.43/398.70
  6. Step 6: Final answer
    x = 435.92

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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.