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Finding the Fourth Proportional to 391.23, 538.70 and 308.31

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Solution

The fourth proportional to 391.23, 538.70 and 308.31 is: 424.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.23 : 538.70 = 308.31 : x
  2. Step 2: Convert to fraction form
    391.23/538.70 = 308.31/x
  3. Step 3: Cross multiply
    391.23x = 538.70 × 308.31
  4. Step 4: Simplify right side
    391.23x = 166,084.77
  5. Step 5: Solve for x
    x = 166,084.77/391.23
  6. Step 6: Final answer
    x = 424.52

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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.