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Finding the Fourth Proportional to 318.86, 478.19 and 123.78

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Solution

The fourth proportional to 318.86, 478.19 and 123.78 is: 185.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.86 : 478.19 = 123.78 : x
  2. Step 2: Convert to fraction form
    318.86/478.19 = 123.78/x
  3. Step 3: Cross multiply
    318.86x = 478.19 × 123.78
  4. Step 4: Simplify right side
    318.86x = 59,189.74
  5. Step 5: Solve for x
    x = 59,189.74/318.86
  6. Step 6: Final answer
    x = 185.63

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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.