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Finding the Fourth Proportional to 189.45, 261.32 and 142.80

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Solution

The fourth proportional to 189.45, 261.32 and 142.80 is: 196.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    189.45 : 261.32 = 142.80 : x
  2. Step 2: Convert to fraction form
    189.45/261.32 = 142.80/x
  3. Step 3: Cross multiply
    189.45x = 261.32 × 142.80
  4. Step 4: Simplify right side
    189.45x = 37,316.50
  5. Step 5: Solve for x
    x = 37,316.50/189.45
  6. Step 6: Final answer
    x = 196.97

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.