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Finding the Fourth Proportional to 211.03, 316.53 and 81.03

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Solution

The fourth proportional to 211.03, 316.53 and 81.03 is: 121.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.03 : 316.53 = 81.03 : x
  2. Step 2: Convert to fraction form
    211.03/316.53 = 81.03/x
  3. Step 3: Cross multiply
    211.03x = 316.53 × 81.03
  4. Step 4: Simplify right side
    211.03x = 25,647.17
  5. Step 5: Solve for x
    x = 25,647.17/211.03
  6. Step 6: Final answer
    x = 121.53

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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.