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Finding the Fourth Proportional to 420.80, 580.71 and 231.75

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Solution

The fourth proportional to 420.80, 580.71 and 231.75 is: 319.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.80 : 580.71 = 231.75 : x
  2. Step 2: Convert to fraction form
    420.80/580.71 = 231.75/x
  3. Step 3: Cross multiply
    420.80x = 580.71 × 231.75
  4. Step 4: Simplify right side
    420.80x = 134,579.54
  5. Step 5: Solve for x
    x = 134,579.54/420.80
  6. Step 6: Final answer
    x = 319.82

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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.