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Finding the Fourth Proportional to 258.98, 389.85 and 198.86

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Solution

The fourth proportional to 258.98, 389.85 and 198.86 is: 299.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.98 : 389.85 = 198.86 : x
  2. Step 2: Convert to fraction form
    258.98/389.85 = 198.86/x
  3. Step 3: Cross multiply
    258.98x = 389.85 × 198.86
  4. Step 4: Simplify right side
    258.98x = 77,525.57
  5. Step 5: Solve for x
    x = 77,525.57/258.98
  6. Step 6: Final answer
    x = 299.35

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.