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Finding the Fourth Proportional to 420.13, 579.78 and 245.47

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Solution

The fourth proportional to 420.13, 579.78 and 245.47 is: 338.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.13 : 579.78 = 245.47 : x
  2. Step 2: Convert to fraction form
    420.13/579.78 = 245.47/x
  3. Step 3: Cross multiply
    420.13x = 579.78 × 245.47
  4. Step 4: Simplify right side
    420.13x = 142,317.37
  5. Step 5: Solve for x
    x = 142,317.37/420.13
  6. Step 6: Final answer
    x = 338.75

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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.