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Finding the Fourth Proportional to 298.80, 409.02 and 289.20

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Solution

The fourth proportional to 298.80, 409.02 and 289.20 is: 395.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    298.80 : 409.02 = 289.20 : x
  2. Step 2: Convert to fraction form
    298.80/409.02 = 289.20/x
  3. Step 3: Cross multiply
    298.80x = 409.02 × 289.20
  4. Step 4: Simplify right side
    298.80x = 118,288.58
  5. Step 5: Solve for x
    x = 118,288.58/298.80
  6. Step 6: Final answer
    x = 395.88

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.