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Finding the Fourth Proportional to 311.55, 429.79 and 199.45

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Solution

The fourth proportional to 311.55, 429.79 and 199.45 is: 275.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.55 : 429.79 = 199.45 : x
  2. Step 2: Convert to fraction form
    311.55/429.79 = 199.45/x
  3. Step 3: Cross multiply
    311.55x = 429.79 × 199.45
  4. Step 4: Simplify right side
    311.55x = 85,719.61
  5. Step 5: Solve for x
    x = 85,719.61/311.55
  6. Step 6: Final answer
    x = 275.14

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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.