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Finding the Fourth Proportional to 70.30, 105.52 and 31.81

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Solution

The fourth proportional to 70.30, 105.52 and 31.81 is: 47.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.30 : 105.52 = 31.81 : x
  2. Step 2: Convert to fraction form
    70.30/105.52 = 31.81/x
  3. Step 3: Cross multiply
    70.30x = 105.52 × 31.81
  4. Step 4: Simplify right side
    70.30x = 3,356.59
  5. Step 5: Solve for x
    x = 3,356.59/70.30
  6. Step 6: Final answer
    x = 47.75

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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.