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Finding the Fourth Proportional to 289.20, 399.09 and 158.20

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Solution

The fourth proportional to 289.20, 399.09 and 158.20 is: 218.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.20 : 399.09 = 158.20 : x
  2. Step 2: Convert to fraction form
    289.20/399.09 = 158.20/x
  3. Step 3: Cross multiply
    289.20x = 399.09 × 158.20
  4. Step 4: Simplify right side
    289.20x = 63,137.88
  5. Step 5: Solve for x
    x = 63,137.88/289.20
  6. Step 6: Final answer
    x = 218.32

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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.