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Finding the Fourth Proportional to 189.39, 283.80 and 128.31

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Solution

The fourth proportional to 189.39, 283.80 and 128.31 is: 192.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    189.39 : 283.80 = 128.31 : x
  2. Step 2: Convert to fraction form
    189.39/283.80 = 128.31/x
  3. Step 3: Cross multiply
    189.39x = 283.80 × 128.31
  4. Step 4: Simplify right side
    189.39x = 36,415.57
  5. Step 5: Solve for x
    x = 36,415.57/189.39
  6. Step 6: Final answer
    x = 192.28

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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.