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Finding the Fourth Proportional to 109.90, 165.71 and 108.72

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Solution

The fourth proportional to 109.90, 165.71 and 108.72 is: 163.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.90 : 165.71 = 108.72 : x
  2. Step 2: Convert to fraction form
    109.90/165.71 = 108.72/x
  3. Step 3: Cross multiply
    109.90x = 165.71 × 108.72
  4. Step 4: Simplify right side
    109.90x = 18,015.99
  5. Step 5: Solve for x
    x = 18,015.99/109.90
  6. Step 6: Final answer
    x = 163.93

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.