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Finding the Fourth Proportional to 78.76, 108.60 and 63.28

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Solution

The fourth proportional to 78.76, 108.60 and 63.28 is: 87.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.76 : 108.60 = 63.28 : x
  2. Step 2: Convert to fraction form
    78.76/108.60 = 63.28/x
  3. Step 3: Cross multiply
    78.76x = 108.60 × 63.28
  4. Step 4: Simplify right side
    78.76x = 6,872.21
  5. Step 5: Solve for x
    x = 6,872.21/78.76
  6. Step 6: Final answer
    x = 87.26

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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.