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Finding the Fourth Proportional to 388.40, 582.60 and 385.70

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Solution

The fourth proportional to 388.40, 582.60 and 385.70 is: 578.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.40 : 582.60 = 385.70 : x
  2. Step 2: Convert to fraction form
    388.40/582.60 = 385.70/x
  3. Step 3: Cross multiply
    388.40x = 582.60 × 385.70
  4. Step 4: Simplify right side
    388.40x = 224,708.82
  5. Step 5: Solve for x
    x = 224,708.82/388.40
  6. Step 6: Final answer
    x = 578.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.