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Finding the Fourth Proportional to 629.90, 869.34 and 381.22

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Solution

The fourth proportional to 629.90, 869.34 and 381.22 is: 526.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.90 : 869.34 = 381.22 : x
  2. Step 2: Convert to fraction form
    629.90/869.34 = 381.22/x
  3. Step 3: Cross multiply
    629.90x = 869.34 × 381.22
  4. Step 4: Simplify right side
    629.90x = 331,406.85
  5. Step 5: Solve for x
    x = 331,406.85/629.90
  6. Step 6: Final answer
    x = 526.12

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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.