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Finding the Fourth Proportional to 70.61, 105.91 and 30.05

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Solution

The fourth proportional to 70.61, 105.91 and 30.05 is: 45.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.61 : 105.91 = 30.05 : x
  2. Step 2: Convert to fraction form
    70.61/105.91 = 30.05/x
  3. Step 3: Cross multiply
    70.61x = 105.91 × 30.05
  4. Step 4: Simplify right side
    70.61x = 3,181.99
  5. Step 5: Solve for x
    x = 3,181.99/70.61
  6. Step 6: Final answer
    x = 45.07

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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.