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Finding the Fourth Proportional to 90.80, 136.35 and 90.09

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Solution

The fourth proportional to 90.80, 136.35 and 90.09 is: 135.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.80 : 136.35 = 90.09 : x
  2. Step 2: Convert to fraction form
    90.80/136.35 = 90.09/x
  3. Step 3: Cross multiply
    90.80x = 136.35 × 90.09
  4. Step 4: Simplify right side
    90.80x = 12,283.77
  5. Step 5: Solve for x
    x = 12,283.77/90.80
  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.