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Finding the Fourth Proportional to 165.90, 229.50 and 138.21

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Solution

The fourth proportional to 165.90, 229.50 and 138.21 is: 191.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    165.90 : 229.50 = 138.21 : x
  2. Step 2: Convert to fraction form
    165.90/229.50 = 138.21/x
  3. Step 3: Cross multiply
    165.90x = 229.50 × 138.21
  4. Step 4: Simplify right side
    165.90x = 31,719.20
  5. Step 5: Solve for x
    x = 31,719.20/165.90
  6. Step 6: Final answer
    x = 191.19

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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.