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Finding the Fourth Proportional to 420.46, 580.20 and 245.80

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Solution

The fourth proportional to 420.46, 580.20 and 245.80 is: 339.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.46 : 580.20 = 245.80 : x
  2. Step 2: Convert to fraction form
    420.46/580.20 = 245.80/x
  3. Step 3: Cross multiply
    420.46x = 580.20 × 245.80
  4. Step 4: Simplify right side
    420.46x = 142,613.16
  5. Step 5: Solve for x
    x = 142,613.16/420.46
  6. Step 6: Final answer
    x = 339.18

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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.