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Finding the Fourth Proportional to 285.21, 393.78 and 180.42

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Solution

The fourth proportional to 285.21, 393.78 and 180.42 is: 249.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.21 : 393.78 = 180.42 : x
  2. Step 2: Convert to fraction form
    285.21/393.78 = 180.42/x
  3. Step 3: Cross multiply
    285.21x = 393.78 × 180.42
  4. Step 4: Simplify right side
    285.21x = 71,045.79
  5. Step 5: Solve for x
    x = 71,045.79/285.21
  6. Step 6: Final answer
    x = 249.10

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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.