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Finding the Fourth Proportional to 393.42, 542.94 and 306.21

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Solution

The fourth proportional to 393.42, 542.94 and 306.21 is: 422.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.42 : 542.94 = 306.21 : x
  2. Step 2: Convert to fraction form
    393.42/542.94 = 306.21/x
  3. Step 3: Cross multiply
    393.42x = 542.94 × 306.21
  4. Step 4: Simplify right side
    393.42x = 166,253.66
  5. Step 5: Solve for x
    x = 166,253.66/393.42
  6. Step 6: Final answer
    x = 422.59

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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.