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Finding the Fourth Proportional to 149.20, 205.86 and 90.20

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Solution

The fourth proportional to 149.20, 205.86 and 90.20 is: 124.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.20 : 205.86 = 90.20 : x
  2. Step 2: Convert to fraction form
    149.20/205.86 = 90.20/x
  3. Step 3: Cross multiply
    149.20x = 205.86 × 90.20
  4. Step 4: Simplify right side
    149.20x = 18,568.57
  5. Step 5: Solve for x
    x = 18,568.57/149.20
  6. Step 6: Final answer
    x = 124.45

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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.