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Finding the Fourth Proportional to 72.09, 99.51 and 42.61

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Solution

The fourth proportional to 72.09, 99.51 and 42.61 is: 58.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.09 : 99.51 = 42.61 : x
  2. Step 2: Convert to fraction form
    72.09/99.51 = 42.61/x
  3. Step 3: Cross multiply
    72.09x = 99.51 × 42.61
  4. Step 4: Simplify right side
    72.09x = 4,240.14
  5. Step 5: Solve for x
    x = 4,240.14/72.09
  6. Step 6: Final answer
    x = 58.82

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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.