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Finding the Fourth Proportional to 72.78, 100.36 and 63.46

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Solution

The fourth proportional to 72.78, 100.36 and 63.46 is: 87.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.78 : 100.36 = 63.46 : x
  2. Step 2: Convert to fraction form
    72.78/100.36 = 63.46/x
  3. Step 3: Cross multiply
    72.78x = 100.36 × 63.46
  4. Step 4: Simplify right side
    72.78x = 6,368.85
  5. Step 5: Solve for x
    x = 6,368.85/72.78
  6. Step 6: Final answer
    x = 87.51

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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.