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Finding the Fourth Proportional to 143.47, 214.80 and 128.89

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Solution

The fourth proportional to 143.47, 214.80 and 128.89 is: 192.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.47 : 214.80 = 128.89 : x
  2. Step 2: Convert to fraction form
    143.47/214.80 = 128.89/x
  3. Step 3: Cross multiply
    143.47x = 214.80 × 128.89
  4. Step 4: Simplify right side
    143.47x = 27,685.57
  5. Step 5: Solve for x
    x = 27,685.57/143.47
  6. Step 6: Final answer
    x = 192.97

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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.