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Finding the Fourth Proportional to 388.71, 580.21 and 342.57

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Solution

The fourth proportional to 388.71, 580.21 and 342.57 is: 511.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.71 : 580.21 = 342.57 : x
  2. Step 2: Convert to fraction form
    388.71/580.21 = 342.57/x
  3. Step 3: Cross multiply
    388.71x = 580.21 × 342.57
  4. Step 4: Simplify right side
    388.71x = 198,766.36
  5. Step 5: Solve for x
    x = 198,766.36/388.71
  6. Step 6: Final answer
    x = 511.36

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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.