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Finding the Fourth Proportional to 206.08, 309.20 and 90.47

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Solution

The fourth proportional to 206.08, 309.20 and 90.47 is: 135.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.08 : 309.20 = 90.47 : x
  2. Step 2: Convert to fraction form
    206.08/309.20 = 90.47/x
  3. Step 3: Cross multiply
    206.08x = 309.20 × 90.47
  4. Step 4: Simplify right side
    206.08x = 27,973.64
  5. Step 5: Solve for x
    x = 27,973.64/206.08
  6. Step 6: Final answer
    x = 135.74

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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.