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Finding the Fourth Proportional to 172.41, 257.82 and 128.57

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Solution

The fourth proportional to 172.41, 257.82 and 128.57 is: 192.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.41 : 257.82 = 128.57 : x
  2. Step 2: Convert to fraction form
    172.41/257.82 = 128.57/x
  3. Step 3: Cross multiply
    172.41x = 257.82 × 128.57
  4. Step 4: Simplify right side
    172.41x = 33,146.63
  5. Step 5: Solve for x
    x = 33,146.63/172.41
  6. Step 6: Final answer
    x = 192.25

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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.