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Finding the Fourth Proportional to 320.79, 442.70 and 189.80

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Solution

The fourth proportional to 320.79, 442.70 and 189.80 is: 261.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.79 : 442.70 = 189.80 : x
  2. Step 2: Convert to fraction form
    320.79/442.70 = 189.80/x
  3. Step 3: Cross multiply
    320.79x = 442.70 × 189.80
  4. Step 4: Simplify right side
    320.79x = 84,021.30
  5. Step 5: Solve for x
    x = 84,021.30/320.79
  6. Step 6: Final answer
    x = 261.92

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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.