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Finding the Fourth Proportional to 51.61, 71.20 and 30.88

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Solution

The fourth proportional to 51.61, 71.20 and 30.88 is: 42.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.61 : 71.20 = 30.88 : x
  2. Step 2: Convert to fraction form
    51.61/71.20 = 30.88/x
  3. Step 3: Cross multiply
    51.61x = 71.20 × 30.88
  4. Step 4: Simplify right side
    51.61x = 2,198.50
  5. Step 5: Solve for x
    x = 2,198.50/51.61
  6. Step 6: Final answer
    x = 42.60

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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.