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Finding the Fourth Proportional to 289.28, 399.18 and 158.28

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Solution

The fourth proportional to 289.28, 399.18 and 158.28 is: 218.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.28 : 399.18 = 158.28 : x
  2. Step 2: Convert to fraction form
    289.28/399.18 = 158.28/x
  3. Step 3: Cross multiply
    289.28x = 399.18 × 158.28
  4. Step 4: Simplify right side
    289.28x = 63,182.21
  5. Step 5: Solve for x
    x = 63,182.21/289.28
  6. Step 6: Final answer
    x = 218.42

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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.