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Finding the Fourth Proportional to 72.51, 100.15 and 63.78

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Solution

The fourth proportional to 72.51, 100.15 and 63.78 is: 88.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.51 : 100.15 = 63.78 : x
  2. Step 2: Convert to fraction form
    72.51/100.15 = 63.78/x
  3. Step 3: Cross multiply
    72.51x = 100.15 × 63.78
  4. Step 4: Simplify right side
    72.51x = 6,387.56
  5. Step 5: Solve for x
    x = 6,387.56/72.51
  6. Step 6: Final answer
    x = 88.09

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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.