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Finding the Fourth Proportional to 319.78, 479.67 and 127.42

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Solution

The fourth proportional to 319.78, 479.67 and 127.42 is: 191.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.78 : 479.67 = 127.42 : x
  2. Step 2: Convert to fraction form
    319.78/479.67 = 127.42/x
  3. Step 3: Cross multiply
    319.78x = 479.67 × 127.42
  4. Step 4: Simplify right side
    319.78x = 61,119.55
  5. Step 5: Solve for x
    x = 61,119.55/319.78
  6. Step 6: Final answer
    x = 191.13

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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.