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Finding the Fourth Proportional to 629.15, 867.78 and 393.21

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Solution

The fourth proportional to 629.15, 867.78 and 393.21 is: 542.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.15 : 867.78 = 393.21 : x
  2. Step 2: Convert to fraction form
    629.15/867.78 = 393.21/x
  3. Step 3: Cross multiply
    629.15x = 867.78 × 393.21
  4. Step 4: Simplify right side
    629.15x = 341,219.77
  5. Step 5: Solve for x
    x = 341,219.77/629.15
  6. Step 6: Final answer
    x = 542.35

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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.