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Finding the Fourth Proportional to 75.28, 103.58 and 74.78

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Solution

The fourth proportional to 75.28, 103.58 and 74.78 is: 102.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.28 : 103.58 = 74.78 : x
  2. Step 2: Convert to fraction form
    75.28/103.58 = 74.78/x
  3. Step 3: Cross multiply
    75.28x = 103.58 × 74.78
  4. Step 4: Simplify right side
    75.28x = 7,745.71
  5. Step 5: Solve for x
    x = 7,745.71/75.28
  6. Step 6: Final answer
    x = 102.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.