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Finding the Fourth Proportional to 420.15, 579.65 and 254.31

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Solution

The fourth proportional to 420.15, 579.65 and 254.31 is: 350.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.15 : 579.65 = 254.31 : x
  2. Step 2: Convert to fraction form
    420.15/579.65 = 254.31/x
  3. Step 3: Cross multiply
    420.15x = 579.65 × 254.31
  4. Step 4: Simplify right side
    420.15x = 147,407.35
  5. Step 5: Solve for x
    x = 147,407.35/420.15
  6. Step 6: Final answer
    x = 350.84

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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.