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Finding the Fourth Proportional to 386.80, 533.92 and 239.40

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Solution

The fourth proportional to 386.80, 533.92 and 239.40 is: 330.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.80 : 533.92 = 239.40 : x
  2. Step 2: Convert to fraction form
    386.80/533.92 = 239.40/x
  3. Step 3: Cross multiply
    386.80x = 533.92 × 239.40
  4. Step 4: Simplify right side
    386.80x = 127,820.45
  5. Step 5: Solve for x
    x = 127,820.45/386.80
  6. Step 6: Final answer
    x = 330.46

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.