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Finding the Fourth Proportional to 206.65, 309.99 and 115.30

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Solution

The fourth proportional to 206.65, 309.99 and 115.30 is: 172.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.65 : 309.99 = 115.30 : x
  2. Step 2: Convert to fraction form
    206.65/309.99 = 115.30/x
  3. Step 3: Cross multiply
    206.65x = 309.99 × 115.30
  4. Step 4: Simplify right side
    206.65x = 35,741.85
  5. Step 5: Solve for x
    x = 35,741.85/206.65
  6. Step 6: Final answer
    x = 172.96

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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.