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Finding the Fourth Proportional to 431.40, 646.75 and 225.79

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Solution

The fourth proportional to 431.40, 646.75 and 225.79 is: 338.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.40 : 646.75 = 225.79 : x
  2. Step 2: Convert to fraction form
    431.40/646.75 = 225.79/x
  3. Step 3: Cross multiply
    431.40x = 646.75 × 225.79
  4. Step 4: Simplify right side
    431.40x = 146,029.68
  5. Step 5: Solve for x
    x = 146,029.68/431.40
  6. Step 6: Final answer
    x = 338.50

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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.