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Finding the Fourth Proportional to 74.78, 103.28 and 63.18

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Solution

The fourth proportional to 74.78, 103.28 and 63.18 is: 87.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.78 : 103.28 = 63.18 : x
  2. Step 2: Convert to fraction form
    74.78/103.28 = 63.18/x
  3. Step 3: Cross multiply
    74.78x = 103.28 × 63.18
  4. Step 4: Simplify right side
    74.78x = 6,524.91
  5. Step 5: Solve for x
    x = 6,524.91/74.78
  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.