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Finding the Fourth Proportional to 51.55, 71.10 and 30.81

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Solution

The fourth proportional to 51.55, 71.10 and 30.81 is: 42.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.55 : 71.10 = 30.81 : x
  2. Step 2: Convert to fraction form
    51.55/71.10 = 30.81/x
  3. Step 3: Cross multiply
    51.55x = 71.10 × 30.81
  4. Step 4: Simplify right side
    51.55x = 2,190.59
  5. Step 5: Solve for x
    x = 2,190.59/51.55
  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.