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Finding the Fourth Proportional to 431.87, 647.53 and 215.43

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Solution

The fourth proportional to 431.87, 647.53 and 215.43 is: 323.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.87 : 647.53 = 215.43 : x
  2. Step 2: Convert to fraction form
    431.87/647.53 = 215.43/x
  3. Step 3: Cross multiply
    431.87x = 647.53 × 215.43
  4. Step 4: Simplify right side
    431.87x = 139,494.42
  5. Step 5: Solve for x
    x = 139,494.42/431.87
  6. Step 6: Final answer
    x = 323.00

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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.