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Finding the Fourth Proportional to 386.40, 533.28 and 379.20

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Solution

The fourth proportional to 386.40, 533.28 and 379.20 is: 523.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.40 : 533.28 = 379.20 : x
  2. Step 2: Convert to fraction form
    386.40/533.28 = 379.20/x
  3. Step 3: Cross multiply
    386.40x = 533.28 × 379.20
  4. Step 4: Simplify right side
    386.40x = 202,219.78
  5. Step 5: Solve for x
    x = 202,219.78/386.40
  6. Step 6: Final answer
    x = 523.34

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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.