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Finding the Fourth Proportional to 431.55, 647.36 and 171.42

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Solution

The fourth proportional to 431.55, 647.36 and 171.42 is: 257.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.55 : 647.36 = 171.42 : x
  2. Step 2: Convert to fraction form
    431.55/647.36 = 171.42/x
  3. Step 3: Cross multiply
    431.55x = 647.36 × 171.42
  4. Step 4: Simplify right side
    431.55x = 110,969.59
  5. Step 5: Solve for x
    x = 110,969.59/431.55
  6. Step 6: Final answer
    x = 257.14

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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.