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Finding the Fourth Proportional to 395.70, 542.82 and 378.90

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Solution

The fourth proportional to 395.70, 542.82 and 378.90 is: 519.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    395.70 : 542.82 = 378.90 : x
  2. Step 2: Convert to fraction form
    395.70/542.82 = 378.90/x
  3. Step 3: Cross multiply
    395.70x = 542.82 × 378.90
  4. Step 4: Simplify right side
    395.70x = 205,674.50
  5. Step 5: Solve for x
    x = 205,674.50/395.70
  6. Step 6: Final answer
    x = 519.77

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.