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Finding the Fourth Proportional to 289.26, 398.88 and 172.80

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Solution

The fourth proportional to 289.26, 398.88 and 172.80 is: 238.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.26 : 398.88 = 172.80 : x
  2. Step 2: Convert to fraction form
    289.26/398.88 = 172.80/x
  3. Step 3: Cross multiply
    289.26x = 398.88 × 172.80
  4. Step 4: Simplify right side
    289.26x = 68,926.46
  5. Step 5: Solve for x
    x = 68,926.46/289.26
  6. Step 6: Final answer
    x = 238.29

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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.