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Finding the Fourth Proportional to 72.90, 100.51 and 63.65

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Solution

The fourth proportional to 72.90, 100.51 and 63.65 is: 87.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.90 : 100.51 = 63.65 : x
  2. Step 2: Convert to fraction form
    72.90/100.51 = 63.65/x
  3. Step 3: Cross multiply
    72.90x = 100.51 × 63.65
  4. Step 4: Simplify right side
    72.90x = 6,397.55
  5. Step 5: Solve for x
    x = 6,397.55/72.90
  6. Step 6: Final answer
    x = 87.76

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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.