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Finding the Fourth Proportional to 108.72, 149.67 and 89.28

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Solution

The fourth proportional to 108.72, 149.67 and 89.28 is: 122.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.72 : 149.67 = 89.28 : x
  2. Step 2: Convert to fraction form
    108.72/149.67 = 89.28/x
  3. Step 3: Cross multiply
    108.72x = 149.67 × 89.28
  4. Step 4: Simplify right side
    108.72x = 13,362.54
  5. Step 5: Solve for x
    x = 13,362.54/108.72
  6. Step 6: Final answer
    x = 122.91

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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.