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Finding the Fourth Proportional to 394.28, 588.05 and 387.80

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Solution

The fourth proportional to 394.28, 588.05 and 387.80 is: 578.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    394.28 : 588.05 = 387.80 : x
  2. Step 2: Convert to fraction form
    394.28/588.05 = 387.80/x
  3. Step 3: Cross multiply
    394.28x = 588.05 × 387.80
  4. Step 4: Simplify right side
    394.28x = 228,045.79
  5. Step 5: Solve for x
    x = 228,045.79/394.28
  6. Step 6: Final answer
    x = 578.39

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.