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Finding the Fourth Proportional to 73.80, 102.10 and 72.20

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Solution

The fourth proportional to 73.80, 102.10 and 72.20 is: 99.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    73.80 : 102.10 = 72.20 : x
  2. Step 2: Convert to fraction form
    73.80/102.10 = 72.20/x
  3. Step 3: Cross multiply
    73.80x = 102.10 × 72.20
  4. Step 4: Simplify right side
    73.80x = 7,371.62
  5. Step 5: Solve for x
    x = 7,371.62/73.80
  6. Step 6: Final answer
    x = 99.89

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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.