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Finding the Fourth Proportional to 431.29, 647.20 and 171.42

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Solution

The fourth proportional to 431.29, 647.20 and 171.42 is: 257.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.29 : 647.20 = 171.42 : x
  2. Step 2: Convert to fraction form
    431.29/647.20 = 171.42/x
  3. Step 3: Cross multiply
    431.29x = 647.20 × 171.42
  4. Step 4: Simplify right side
    431.29x = 110,940.81
  5. Step 5: Solve for x
    x = 110,940.81/431.29
  6. Step 6: Final answer
    x = 257.23

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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.