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Finding the Fourth Proportional to 388.28, 582.56 and 215.15

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Solution

The fourth proportional to 388.28, 582.56 and 215.15 is: 322.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.28 : 582.56 = 215.15 : x
  2. Step 2: Convert to fraction form
    388.28/582.56 = 215.15/x
  3. Step 3: Cross multiply
    388.28x = 582.56 × 215.15
  4. Step 4: Simplify right side
    388.28x = 125,333.80
  5. Step 5: Solve for x
    x = 125,333.80/388.28
  6. Step 6: Final answer
    x = 322.80

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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.