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Finding the Fourth Proportional to 298.88, 411.20 and 290.80

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Solution

The fourth proportional to 298.88, 411.20 and 290.80 is: 400.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    298.88 : 411.20 = 290.80 : x
  2. Step 2: Convert to fraction form
    298.88/411.20 = 290.80/x
  3. Step 3: Cross multiply
    298.88x = 411.20 × 290.80
  4. Step 4: Simplify right side
    298.88x = 119,576.96
  5. Step 5: Solve for x
    x = 119,576.96/298.88
  6. Step 6: Final answer
    x = 400.08

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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.