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Finding the Fourth Proportional to 137.40, 207.24 and 128.40

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Solution

The fourth proportional to 137.40, 207.24 and 128.40 is: 193.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.40 : 207.24 = 128.40 : x
  2. Step 2: Convert to fraction form
    137.40/207.24 = 128.40/x
  3. Step 3: Cross multiply
    137.40x = 207.24 × 128.40
  4. Step 4: Simplify right side
    137.40x = 26,609.62
  5. Step 5: Solve for x
    x = 26,609.62/137.40
  6. Step 6: Final answer
    x = 193.67

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.