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Finding the Fourth Proportional to 285.17, 393.21 and 245.78

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Solution

The fourth proportional to 285.17, 393.21 and 245.78 is: 338.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.17 : 393.21 = 245.78 : x
  2. Step 2: Convert to fraction form
    285.17/393.21 = 245.78/x
  3. Step 3: Cross multiply
    285.17x = 393.21 × 245.78
  4. Step 4: Simplify right side
    285.17x = 96,643.15
  5. Step 5: Solve for x
    x = 96,643.15/285.17
  6. Step 6: Final answer
    x = 338.90

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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.