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Finding the Fourth Proportional to 165.10, 247.31 and 78.17

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Solution

The fourth proportional to 165.10, 247.31 and 78.17 is: 117.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    165.10 : 247.31 = 78.17 : x
  2. Step 2: Convert to fraction form
    165.10/247.31 = 78.17/x
  3. Step 3: Cross multiply
    165.10x = 247.31 × 78.17
  4. Step 4: Simplify right side
    165.10x = 19,331.21
  5. Step 5: Solve for x
    x = 19,331.21/165.10
  6. Step 6: Final answer
    x = 117.09

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.