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Finding the Fourth Proportional to 336.78, 505.20 and 259.80

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Solution

The fourth proportional to 336.78, 505.20 and 259.80 is: 389.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    336.78 : 505.20 = 259.80 : x
  2. Step 2: Convert to fraction form
    336.78/505.20 = 259.80/x
  3. Step 3: Cross multiply
    336.78x = 505.20 × 259.80
  4. Step 4: Simplify right side
    336.78x = 131,250.96
  5. Step 5: Solve for x
    x = 131,250.96/336.78
  6. Step 6: Final answer
    x = 389.72

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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.