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Finding the Fourth Proportional to 100.42, 137.98 and 80.98

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Solution

The fourth proportional to 100.42, 137.98 and 80.98 is: 111.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.42 : 137.98 = 80.98 : x
  2. Step 2: Convert to fraction form
    100.42/137.98 = 80.98/x
  3. Step 3: Cross multiply
    100.42x = 137.98 × 80.98
  4. Step 4: Simplify right side
    100.42x = 11,173.62
  5. Step 5: Solve for x
    x = 11,173.62/100.42
  6. Step 6: Final answer
    x = 111.27

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.