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Finding the Fourth Proportional to 171.51, 257.28 and 128.22

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Solution

The fourth proportional to 171.51, 257.28 and 128.22 is: 192.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    171.51 : 257.28 = 128.22 : x
  2. Step 2: Convert to fraction form
    171.51/257.28 = 128.22/x
  3. Step 3: Cross multiply
    171.51x = 257.28 × 128.22
  4. Step 4: Simplify right side
    171.51x = 32,988.44
  5. Step 5: Solve for x
    x = 32,988.44/171.51
  6. Step 6: Final answer
    x = 192.34

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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.