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Finding the Fourth Proportional to 108.78, 148.08 and 108.20

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Solution

The fourth proportional to 108.78, 148.08 and 108.20 is: 147.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.78 : 148.08 = 108.20 : x
  2. Step 2: Convert to fraction form
    108.78/148.08 = 108.20/x
  3. Step 3: Cross multiply
    108.78x = 148.08 × 108.20
  4. Step 4: Simplify right side
    108.78x = 16,022.26
  5. Step 5: Solve for x
    x = 16,022.26/108.78
  6. Step 6: Final answer
    x = 147.29

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.