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Finding the Fourth Proportional to 99.80, 137.38 and 72.14

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Solution

The fourth proportional to 99.80, 137.38 and 72.14 is: 99.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.80 : 137.38 = 72.14 : x
  2. Step 2: Convert to fraction form
    99.80/137.38 = 72.14/x
  3. Step 3: Cross multiply
    99.80x = 137.38 × 72.14
  4. Step 4: Simplify right side
    99.80x = 9,910.59
  5. Step 5: Solve for x
    x = 9,910.59/99.80
  6. Step 6: Final answer
    x = 99.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.