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Finding the Fourth Proportional to 320.40, 442.17 and 189.43

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Solution

The fourth proportional to 320.40, 442.17 and 189.43 is: 261.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.40 : 442.17 = 189.43 : x
  2. Step 2: Convert to fraction form
    320.40/442.17 = 189.43/x
  3. Step 3: Cross multiply
    320.40x = 442.17 × 189.43
  4. Step 4: Simplify right side
    320.40x = 83,760.26
  5. Step 5: Solve for x
    x = 83,760.26/320.40
  6. Step 6: Final answer
    x = 261.42

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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.