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Finding the Fourth Proportional to 214.69, 321.23 and 128.07

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Solution

The fourth proportional to 214.69, 321.23 and 128.07 is: 191.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    214.69 : 321.23 = 128.07 : x
  2. Step 2: Convert to fraction form
    214.69/321.23 = 128.07/x
  3. Step 3: Cross multiply
    214.69x = 321.23 × 128.07
  4. Step 4: Simplify right side
    214.69x = 41,139.93
  5. Step 5: Solve for x
    x = 41,139.93/214.69
  6. Step 6: Final answer
    x = 191.62

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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.