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Finding the Fourth Proportional to 34.25, 47.28 and 30.78

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Solution

The fourth proportional to 34.25, 47.28 and 30.78 is: 42.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    34.25 : 47.28 = 30.78 : x
  2. Step 2: Convert to fraction form
    34.25/47.28 = 30.78/x
  3. Step 3: Cross multiply
    34.25x = 47.28 × 30.78
  4. Step 4: Simplify right side
    34.25x = 1,455.28
  5. Step 5: Solve for x
    x = 1,455.28/34.25
  6. Step 6: Final answer
    x = 42.50

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.