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Finding the Fourth Proportional to 74.82, 111.51 and 72.90

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Solution

The fourth proportional to 74.82, 111.51 and 72.90 is: 108.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.82 : 111.51 = 72.90 : x
  2. Step 2: Convert to fraction form
    74.82/111.51 = 72.90/x
  3. Step 3: Cross multiply
    74.82x = 111.51 × 72.90
  4. Step 4: Simplify right side
    74.82x = 8,129.08
  5. Step 5: Solve for x
    x = 8,129.08/74.82
  6. Step 6: Final answer
    x = 108.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.