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Finding the Fourth Proportional to 51.50, 71.09 and 30.78

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Solution

The fourth proportional to 51.50, 71.09 and 30.78 is: 42.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.50 : 71.09 = 30.78 : x
  2. Step 2: Convert to fraction form
    51.50/71.09 = 30.78/x
  3. Step 3: Cross multiply
    51.50x = 71.09 × 30.78
  4. Step 4: Simplify right side
    51.50x = 2,188.00
  5. Step 5: Solve for x
    x = 2,188.00/51.50
  6. Step 6: Final answer
    x = 42.49

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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.