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Finding the Fourth Proportional to 319.78, 479.69 and 136.99

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Solution

The fourth proportional to 319.78, 479.69 and 136.99 is: 205.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.78 : 479.69 = 136.99 : x
  2. Step 2: Convert to fraction form
    319.78/479.69 = 136.99/x
  3. Step 3: Cross multiply
    319.78x = 479.69 × 136.99
  4. Step 4: Simplify right side
    319.78x = 65,712.05
  5. Step 5: Solve for x
    x = 65,712.05/319.78
  6. Step 6: Final answer
    x = 205.49

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.