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Finding the Fourth Proportional to 34.62, 47.80 and 21.72

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Solution

The fourth proportional to 34.62, 47.80 and 21.72 is: 29.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    34.62 : 47.80 = 21.72 : x
  2. Step 2: Convert to fraction form
    34.62/47.80 = 21.72/x
  3. Step 3: Cross multiply
    34.62x = 47.80 × 21.72
  4. Step 4: Simplify right side
    34.62x = 1,038.22
  5. Step 5: Solve for x
    x = 1,038.22/34.62
  6. Step 6: Final answer
    x = 29.99

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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.