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Finding the Fourth Proportional to 285.49, 394.05 and 238.78

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Solution

The fourth proportional to 285.49, 394.05 and 238.78 is: 329.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.49 : 394.05 = 238.78 : x
  2. Step 2: Convert to fraction form
    285.49/394.05 = 238.78/x
  3. Step 3: Cross multiply
    285.49x = 394.05 × 238.78
  4. Step 4: Simplify right side
    285.49x = 94,090.07
  5. Step 5: Solve for x
    x = 94,090.07/285.49
  6. Step 6: Final answer
    x = 329.57

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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.