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Finding the Fourth Proportional to 419.91, 579.56 and 287.40

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Solution

The fourth proportional to 419.91, 579.56 and 287.40 is: 396.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.91 : 579.56 = 287.40 : x
  2. Step 2: Convert to fraction form
    419.91/579.56 = 287.40/x
  3. Step 3: Cross multiply
    419.91x = 579.56 × 287.40
  4. Step 4: Simplify right side
    419.91x = 166,563.02
  5. Step 5: Solve for x
    x = 166,563.02/419.91
  6. Step 6: Final answer
    x = 396.66

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.