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Finding the Fourth Proportional to 636.78, 879.10 and 388.14

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Solution

The fourth proportional to 636.78, 879.10 and 388.14 is: 535.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.78 : 879.10 = 388.14 : x
  2. Step 2: Convert to fraction form
    636.78/879.10 = 388.14/x
  3. Step 3: Cross multiply
    636.78x = 879.10 × 388.14
  4. Step 4: Simplify right side
    636.78x = 341,213.87
  5. Step 5: Solve for x
    x = 341,213.87/636.78
  6. Step 6: Final answer
    x = 535.84

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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.