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Finding the Fourth Proportional to 201.85, 302.78 and 115.21

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Solution

The fourth proportional to 201.85, 302.78 and 115.21 is: 172.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    201.85 : 302.78 = 115.21 : x
  2. Step 2: Convert to fraction form
    201.85/302.78 = 115.21/x
  3. Step 3: Cross multiply
    201.85x = 302.78 × 115.21
  4. Step 4: Simplify right side
    201.85x = 34,883.28
  5. Step 5: Solve for x
    x = 34,883.28/201.85
  6. Step 6: Final answer
    x = 172.82

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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.