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Finding the Fourth Proportional to 207.80, 311.51 and 115.11

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Solution

The fourth proportional to 207.80, 311.51 and 115.11 is: 172.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.80 : 311.51 = 115.11 : x
  2. Step 2: Convert to fraction form
    207.80/311.51 = 115.11/x
  3. Step 3: Cross multiply
    207.80x = 311.51 × 115.11
  4. Step 4: Simplify right side
    207.80x = 35,857.34
  5. Step 5: Solve for x
    x = 35,857.34/207.80
  6. Step 6: Final answer
    x = 172.56

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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.