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Finding the Fourth Proportional to 205.74, 308.72 and 90.17

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Solution

The fourth proportional to 205.74, 308.72 and 90.17 is: 135.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.74 : 308.72 = 90.17 : x
  2. Step 2: Convert to fraction form
    205.74/308.72 = 90.17/x
  3. Step 3: Cross multiply
    205.74x = 308.72 × 90.17
  4. Step 4: Simplify right side
    205.74x = 27,835.29
  5. Step 5: Solve for x
    x = 27,835.29/205.74
  6. Step 6: Final answer
    x = 135.29

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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.