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Finding the Fourth Proportional to 51.99, 71.79 and 39.72

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Solution

The fourth proportional to 51.99, 71.79 and 39.72 is: 54.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.99 : 71.79 = 39.72 : x
  2. Step 2: Convert to fraction form
    51.99/71.79 = 39.72/x
  3. Step 3: Cross multiply
    51.99x = 71.79 × 39.72
  4. Step 4: Simplify right side
    51.99x = 2,851.50
  5. Step 5: Solve for x
    x = 2,851.50/51.99
  6. Step 6: Final answer
    x = 54.85

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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.