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Finding the Fourth Proportional to 47.15, 70.74 and 30.90

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Solution

The fourth proportional to 47.15, 70.74 and 30.90 is: 46.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.15 : 70.74 = 30.90 : x
  2. Step 2: Convert to fraction form
    47.15/70.74 = 30.90/x
  3. Step 3: Cross multiply
    47.15x = 70.74 × 30.90
  4. Step 4: Simplify right side
    47.15x = 2,185.87
  5. Step 5: Solve for x
    x = 2,185.87/47.15
  6. Step 6: Final answer
    x = 46.36

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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.