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Finding the Fourth Proportional to 154.21, 212.81 and 88.72

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Solution

The fourth proportional to 154.21, 212.81 and 88.72 is: 122.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.21 : 212.81 = 88.72 : x
  2. Step 2: Convert to fraction form
    154.21/212.81 = 88.72/x
  3. Step 3: Cross multiply
    154.21x = 212.81 × 88.72
  4. Step 4: Simplify right side
    154.21x = 18,880.50
  5. Step 5: Solve for x
    x = 18,880.50/154.21
  6. Step 6: Final answer
    x = 122.43

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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.