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Finding the Fourth Proportional to 207.78, 311.80 and 172.14

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Solution

The fourth proportional to 207.78, 311.80 and 172.14 is: 258.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.78 : 311.80 = 172.14 : x
  2. Step 2: Convert to fraction form
    207.78/311.80 = 172.14/x
  3. Step 3: Cross multiply
    207.78x = 311.80 × 172.14
  4. Step 4: Simplify right side
    207.78x = 53,673.25
  5. Step 5: Solve for x
    x = 53,673.25/207.78
  6. Step 6: Final answer
    x = 258.32

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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.