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Finding the Fourth Proportional to 431.94, 646.19 and 388.20

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Solution

The fourth proportional to 431.94, 646.19 and 388.20 is: 580.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.94 : 646.19 = 388.20 : x
  2. Step 2: Convert to fraction form
    431.94/646.19 = 388.20/x
  3. Step 3: Cross multiply
    431.94x = 646.19 × 388.20
  4. Step 4: Simplify right side
    431.94x = 250,849.02
  5. Step 5: Solve for x
    x = 250,849.02/431.94
  6. Step 6: Final answer
    x = 580.75

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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.