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Finding the Fourth Proportional to 636.64, 878.58 and 388

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Solution

The fourth proportional to 636.64, 878.58 and 388 is: 535.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.64 : 878.58 = 388 : x
  2. Step 2: Convert to fraction form
    636.64/878.58 = 388/x
  3. Step 3: Cross multiply
    636.64x = 878.58 × 388
  4. Step 4: Simplify right side
    636.64x = 340,889.04
  5. Step 5: Solve for x
    x = 340,889.04/636.64
  6. Step 6: Final answer
    x = 535.45

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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.