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Finding the Fourth Proportional to 355.70, 490.78 and 245.40

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Solution

The fourth proportional to 355.70, 490.78 and 245.40 is: 338.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.70 : 490.78 = 245.40 : x
  2. Step 2: Convert to fraction form
    355.70/490.78 = 245.40/x
  3. Step 3: Cross multiply
    355.70x = 490.78 × 245.40
  4. Step 4: Simplify right side
    355.70x = 120,437.41
  5. Step 5: Solve for x
    x = 120,437.41/355.70
  6. Step 6: Final answer
    x = 338.59

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.