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Finding the Fourth Proportional to 289.25, 399.21 and 172.79

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Solution

The fourth proportional to 289.25, 399.21 and 172.79 is: 238.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.25 : 399.21 = 172.79 : x
  2. Step 2: Convert to fraction form
    289.25/399.21 = 172.79/x
  3. Step 3: Cross multiply
    289.25x = 399.21 × 172.79
  4. Step 4: Simplify right side
    289.25x = 68,979.50
  5. Step 5: Solve for x
    x = 68,979.50/289.25
  6. Step 6: Final answer
    x = 238.48

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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.