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Finding the Fourth Proportional to 77.25, 105.90 and 73.20

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Solution

The fourth proportional to 77.25, 105.90 and 73.20 is: 100.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.25 : 105.90 = 73.20 : x
  2. Step 2: Convert to fraction form
    77.25/105.90 = 73.20/x
  3. Step 3: Cross multiply
    77.25x = 105.90 × 73.20
  4. Step 4: Simplify right side
    77.25x = 7,751.88
  5. Step 5: Solve for x
    x = 7,751.88/77.25
  6. Step 6: Final answer
    x = 100.35

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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.