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Finding the Fourth Proportional to 388.72, 582.34 and 215.12

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Solution

The fourth proportional to 388.72, 582.34 and 215.12 is: 322.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.72 : 582.34 = 215.12 : x
  2. Step 2: Convert to fraction form
    388.72/582.34 = 215.12/x
  3. Step 3: Cross multiply
    388.72x = 582.34 × 215.12
  4. Step 4: Simplify right side
    388.72x = 125,274.30
  5. Step 5: Solve for x
    x = 125,274.30/388.72
  6. Step 6: Final answer
    x = 322.28

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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.