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Finding the Fourth Proportional to 421.99, 634.14 and 394.31

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Solution

The fourth proportional to 421.99, 634.14 and 394.31 is: 592.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.99 : 634.14 = 394.31 : x
  2. Step 2: Convert to fraction form
    421.99/634.14 = 394.31/x
  3. Step 3: Cross multiply
    421.99x = 634.14 × 394.31
  4. Step 4: Simplify right side
    421.99x = 250,049.33
  5. Step 5: Solve for x
    x = 250,049.33/421.99
  6. Step 6: Final answer
    x = 592.54

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.