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Finding the Fourth Proportional to 260.80, 390.80 and 199.74

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Solution

The fourth proportional to 260.80, 390.80 and 199.74 is: 299.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.80 : 390.80 = 199.74 : x
  2. Step 2: Convert to fraction form
    260.80/390.80 = 199.74/x
  3. Step 3: Cross multiply
    260.80x = 390.80 × 199.74
  4. Step 4: Simplify right side
    260.80x = 78,058.39
  5. Step 5: Solve for x
    x = 78,058.39/260.80
  6. Step 6: Final answer
    x = 299.30

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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.