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Finding the Fourth Proportional to 289.70, 399.80 and 158.72

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Solution

The fourth proportional to 289.70, 399.80 and 158.72 is: 219.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.70 : 399.80 = 158.72 : x
  2. Step 2: Convert to fraction form
    289.70/399.80 = 158.72/x
  3. Step 3: Cross multiply
    289.70x = 399.80 × 158.72
  4. Step 4: Simplify right side
    289.70x = 63,456.26
  5. Step 5: Solve for x
    x = 63,456.26/289.70
  6. Step 6: Final answer
    x = 219.04

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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.