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Finding the Fourth Proportional to 172.34, 258.29 and 139.91

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Solution

The fourth proportional to 172.34, 258.29 and 139.91 is: 209.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.34 : 258.29 = 139.91 : x
  2. Step 2: Convert to fraction form
    172.34/258.29 = 139.91/x
  3. Step 3: Cross multiply
    172.34x = 258.29 × 139.91
  4. Step 4: Simplify right side
    172.34x = 36,136.65
  5. Step 5: Solve for x
    x = 36,136.65/172.34
  6. Step 6: Final answer
    x = 209.69

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.