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Finding the Fourth Proportional to 70.21, 105.51 and 51.98

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Solution

The fourth proportional to 70.21, 105.51 and 51.98 is: 78.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.21 : 105.51 = 51.98 : x
  2. Step 2: Convert to fraction form
    70.21/105.51 = 51.98/x
  3. Step 3: Cross multiply
    70.21x = 105.51 × 51.98
  4. Step 4: Simplify right side
    70.21x = 5,484.41
  5. Step 5: Solve for x
    x = 5,484.41/70.21
  6. Step 6: Final answer
    x = 78.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.