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Finding the Fourth Proportional to 420.28, 579.86 and 245.56

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Solution

The fourth proportional to 420.28, 579.86 and 245.56 is: 338.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.28 : 579.86 = 245.56 : x
  2. Step 2: Convert to fraction form
    420.28/579.86 = 245.56/x
  3. Step 3: Cross multiply
    420.28x = 579.86 × 245.56
  4. Step 4: Simplify right side
    420.28x = 142,390.42
  5. Step 5: Solve for x
    x = 142,390.42/420.28
  6. Step 6: Final answer
    x = 338.80

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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.