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Finding the Fourth Proportional to 119.85, 165.31 and 90.69

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Solution

The fourth proportional to 119.85, 165.31 and 90.69 is: 125.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    119.85 : 165.31 = 90.69 : x
  2. Step 2: Convert to fraction form
    119.85/165.31 = 90.69/x
  3. Step 3: Cross multiply
    119.85x = 165.31 × 90.69
  4. Step 4: Simplify right side
    119.85x = 14,991.51
  5. Step 5: Solve for x
    x = 14,991.51/119.85
  6. Step 6: Final answer
    x = 125.09

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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.