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Finding the Fourth Proportional to 289.61, 399.65 and 158.61

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Solution

The fourth proportional to 289.61, 399.65 and 158.61 is: 218.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.61 : 399.65 = 158.61 : x
  2. Step 2: Convert to fraction form
    289.61/399.65 = 158.61/x
  3. Step 3: Cross multiply
    289.61x = 399.65 × 158.61
  4. Step 4: Simplify right side
    289.61x = 63,388.49
  5. Step 5: Solve for x
    x = 63,388.49/289.61
  6. Step 6: Final answer
    x = 218.88

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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.