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Finding the Fourth Proportional to 355.42, 490.86 and 289.20

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Solution

The fourth proportional to 355.42, 490.86 and 289.20 is: 399.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.42 : 490.86 = 289.20 : x
  2. Step 2: Convert to fraction form
    355.42/490.86 = 289.20/x
  3. Step 3: Cross multiply
    355.42x = 490.86 × 289.20
  4. Step 4: Simplify right side
    355.42x = 141,958.55
  5. Step 5: Solve for x
    x = 141,958.55/355.42
  6. Step 6: Final answer
    x = 399.41

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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.