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Finding the Fourth Proportional to 69.48, 103.78 and 61.38

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Solution

The fourth proportional to 69.48, 103.78 and 61.38 is: 91.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.48 : 103.78 = 61.38 : x
  2. Step 2: Convert to fraction form
    69.48/103.78 = 61.38/x
  3. Step 3: Cross multiply
    69.48x = 103.78 × 61.38
  4. Step 4: Simplify right side
    69.48x = 6,370.02
  5. Step 5: Solve for x
    x = 6,370.02/69.48
  6. Step 6: Final answer
    x = 91.68

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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.