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Finding the Fourth Proportional to 393.65, 542.45 and 281.30

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Solution

The fourth proportional to 393.65, 542.45 and 281.30 is: 387.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.65 : 542.45 = 281.30 : x
  2. Step 2: Convert to fraction form
    393.65/542.45 = 281.30/x
  3. Step 3: Cross multiply
    393.65x = 542.45 × 281.30
  4. Step 4: Simplify right side
    393.65x = 152,589.12
  5. Step 5: Solve for x
    x = 152,589.12/393.65
  6. Step 6: Final answer
    x = 387.63

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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.