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Finding the Fourth Proportional to 398.42, 549.80 and 223.78

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Solution

The fourth proportional to 398.42, 549.80 and 223.78 is: 308.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.42 : 549.80 = 223.78 : x
  2. Step 2: Convert to fraction form
    398.42/549.80 = 223.78/x
  3. Step 3: Cross multiply
    398.42x = 549.80 × 223.78
  4. Step 4: Simplify right side
    398.42x = 123,034.24
  5. Step 5: Solve for x
    x = 123,034.24/398.42
  6. Step 6: Final answer
    x = 308.81

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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.