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Finding the Fourth Proportional to 431.38, 643.82 and 394.66

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Solution

The fourth proportional to 431.38, 643.82 and 394.66 is: 589.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.38 : 643.82 = 394.66 : x
  2. Step 2: Convert to fraction form
    431.38/643.82 = 394.66/x
  3. Step 3: Cross multiply
    431.38x = 643.82 × 394.66
  4. Step 4: Simplify right side
    431.38x = 254,090.00
  5. Step 5: Solve for x
    x = 254,090.00/431.38
  6. Step 6: Final answer
    x = 589.02

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.