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Finding the Fourth Proportional to 431.68, 647.11 and 215.02

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Solution

The fourth proportional to 431.68, 647.11 and 215.02 is: 322.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.68 : 647.11 = 215.02 : x
  2. Step 2: Convert to fraction form
    431.68/647.11 = 215.02/x
  3. Step 3: Cross multiply
    431.68x = 647.11 × 215.02
  4. Step 4: Simplify right side
    431.68x = 139,141.59
  5. Step 5: Solve for x
    x = 139,141.59/431.68
  6. Step 6: Final answer
    x = 322.33

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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.