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Finding the Fourth Proportional to 431.64, 647.28 and 142.92

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Solution

The fourth proportional to 431.64, 647.28 and 142.92 is: 214.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.64 : 647.28 = 142.92 : x
  2. Step 2: Convert to fraction form
    431.64/647.28 = 142.92/x
  3. Step 3: Cross multiply
    431.64x = 647.28 × 142.92
  4. Step 4: Simplify right side
    431.64x = 92,509.26
  5. Step 5: Solve for x
    x = 92,509.26/431.64
  6. Step 6: Final answer
    x = 214.32

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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.