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Finding the Fourth Proportional to 51.38, 70.90 and 28.38

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Solution

The fourth proportional to 51.38, 70.90 and 28.38 is: 39.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.38 : 70.90 = 28.38 : x
  2. Step 2: Convert to fraction form
    51.38/70.90 = 28.38/x
  3. Step 3: Cross multiply
    51.38x = 70.90 × 28.38
  4. Step 4: Simplify right side
    51.38x = 2,011.72
  5. Step 5: Solve for x
    x = 2,011.72/51.38
  6. Step 6: Final answer
    x = 39.16

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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.