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Finding the Fourth Proportional to 108.78, 150 and 77.70

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Solution

The fourth proportional to 108.78, 150 and 77.70 is: 107.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.78 : 150 = 77.70 : x
  2. Step 2: Convert to fraction form
    108.78/150 = 77.70/x
  3. Step 3: Cross multiply
    108.78x = 150 × 77.70
  4. Step 4: Simplify right side
    108.78x = 11,655
  5. Step 5: Solve for x
    x = 11,655/108.78
  6. Step 6: Final answer
    x = 107.14

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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.