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Finding the Fourth Proportional to 73.16, 109.78 and 72.80

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Solution

The fourth proportional to 73.16, 109.78 and 72.80 is: 109.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    73.16 : 109.78 = 72.80 : x
  2. Step 2: Convert to fraction form
    73.16/109.78 = 72.80/x
  3. Step 3: Cross multiply
    73.16x = 109.78 × 72.80
  4. Step 4: Simplify right side
    73.16x = 7,991.98
  5. Step 5: Solve for x
    x = 7,991.98/73.16
  6. Step 6: Final answer
    x = 109.24

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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.