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Finding the Fourth Proportional to 70.74, 105.62 and 54.72

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Solution

The fourth proportional to 70.74, 105.62 and 54.72 is: 81.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.74 : 105.62 = 54.72 : x
  2. Step 2: Convert to fraction form
    70.74/105.62 = 54.72/x
  3. Step 3: Cross multiply
    70.74x = 105.62 × 54.72
  4. Step 4: Simplify right side
    70.74x = 5,779.25
  5. Step 5: Solve for x
    x = 5,779.25/70.74
  6. Step 6: Final answer
    x = 81.70

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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.