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Finding the Fourth Proportional to 108.16, 149.28 and 85.12

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Solution

The fourth proportional to 108.16, 149.28 and 85.12 is: 117.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.16 : 149.28 = 85.12 : x
  2. Step 2: Convert to fraction form
    108.16/149.28 = 85.12/x
  3. Step 3: Cross multiply
    108.16x = 149.28 × 85.12
  4. Step 4: Simplify right side
    108.16x = 12,706.71
  5. Step 5: Solve for x
    x = 12,706.71/108.16
  6. Step 6: Final answer
    x = 117.48

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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.