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Finding the Fourth Proportional to 73.60, 109.76 and 72.80

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Solution

The fourth proportional to 73.60, 109.76 and 72.80 is: 108.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    73.60 : 109.76 = 72.80 : x
  2. Step 2: Convert to fraction form
    73.60/109.76 = 72.80/x
  3. Step 3: Cross multiply
    73.60x = 109.76 × 72.80
  4. Step 4: Simplify right side
    73.60x = 7,990.53
  5. Step 5: Solve for x
    x = 7,990.53/73.60
  6. Step 6: Final answer
    x = 108.57

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.