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Finding the Fourth Proportional to 137.79, 206.46 and 128.16

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Solution

The fourth proportional to 137.79, 206.46 and 128.16 is: 192.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.79 : 206.46 = 128.16 : x
  2. Step 2: Convert to fraction form
    137.79/206.46 = 128.16/x
  3. Step 3: Cross multiply
    137.79x = 206.46 × 128.16
  4. Step 4: Simplify right side
    137.79x = 26,459.91
  5. Step 5: Solve for x
    x = 26,459.91/137.79
  6. Step 6: Final answer
    x = 192.03

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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.