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Finding the Fourth Proportional to 135.40, 201.98 and 121.72

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Solution

The fourth proportional to 135.40, 201.98 and 121.72 is: 181.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.40 : 201.98 = 121.72 : x
  2. Step 2: Convert to fraction form
    135.40/201.98 = 121.72/x
  3. Step 3: Cross multiply
    135.40x = 201.98 × 121.72
  4. Step 4: Simplify right side
    135.40x = 24,585.01
  5. Step 5: Solve for x
    x = 24,585.01/135.40
  6. Step 6: Final answer
    x = 181.57

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.