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Finding the Fourth Proportional to 388.78, 582.90 and 215.02

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Solution

The fourth proportional to 388.78, 582.90 and 215.02 is: 322.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.78 : 582.90 = 215.02 : x
  2. Step 2: Convert to fraction form
    388.78/582.90 = 215.02/x
  3. Step 3: Cross multiply
    388.78x = 582.90 × 215.02
  4. Step 4: Simplify right side
    388.78x = 125,335.16
  5. Step 5: Solve for x
    x = 125,335.16/388.78
  6. Step 6: Final answer
    x = 322.38

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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.