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Finding the Fourth Proportional to 75.40, 104.47 and 73.78

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Solution

The fourth proportional to 75.40, 104.47 and 73.78 is: 102.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.40 : 104.47 = 73.78 : x
  2. Step 2: Convert to fraction form
    75.40/104.47 = 73.78/x
  3. Step 3: Cross multiply
    75.40x = 104.47 × 73.78
  4. Step 4: Simplify right side
    75.40x = 7,707.35
  5. Step 5: Solve for x
    x = 7,707.35/75.40
  6. Step 6: Final answer
    x = 102.22

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.