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Finding the Fourth Proportional to 208.55, 312.82 and 80.30

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Solution

The fourth proportional to 208.55, 312.82 and 80.30 is: 120.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.55 : 312.82 = 80.30 : x
  2. Step 2: Convert to fraction form
    208.55/312.82 = 80.30/x
  3. Step 3: Cross multiply
    208.55x = 312.82 × 80.30
  4. Step 4: Simplify right side
    208.55x = 25,120.03
  5. Step 5: Solve for x
    x = 25,120.03/208.55
  6. Step 6: Final answer
    x = 120.45

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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.