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Finding the Fourth Proportional to 629.90, 869.41 and 381.38

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Solution

The fourth proportional to 629.90, 869.41 and 381.38 is: 526.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.90 : 869.41 = 381.38 : x
  2. Step 2: Convert to fraction form
    629.90/869.41 = 381.38/x
  3. Step 3: Cross multiply
    629.90x = 869.41 × 381.38
  4. Step 4: Simplify right side
    629.90x = 331,573.68
  5. Step 5: Solve for x
    x = 331,573.68/629.90
  6. Step 6: Final answer
    x = 526.40

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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.