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Finding the Fourth Proportional to 75.80, 113.84 and 72.40

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Solution

The fourth proportional to 75.80, 113.84 and 72.40 is: 108.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.80 : 113.84 = 72.40 : x
  2. Step 2: Convert to fraction form
    75.80/113.84 = 72.40/x
  3. Step 3: Cross multiply
    75.80x = 113.84 × 72.40
  4. Step 4: Simplify right side
    75.80x = 8,242.02
  5. Step 5: Solve for x
    x = 8,242.02/75.80
  6. Step 6: Final answer
    x = 108.73

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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.