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Finding the Fourth Proportional to 319.91, 438.76 and 306.68

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Solution

The fourth proportional to 319.91, 438.76 and 306.68 is: 420.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.91 : 438.76 = 306.68 : x
  2. Step 2: Convert to fraction form
    319.91/438.76 = 306.68/x
  3. Step 3: Cross multiply
    319.91x = 438.76 × 306.68
  4. Step 4: Simplify right side
    319.91x = 134,558.92
  5. Step 5: Solve for x
    x = 134,558.92/319.91
  6. Step 6: Final answer
    x = 420.61

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.