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Finding the Fourth Proportional to 311.70, 429.84 and 187.38

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Solution

The fourth proportional to 311.70, 429.84 and 187.38 is: 258.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.70 : 429.84 = 187.38 : x
  2. Step 2: Convert to fraction form
    311.70/429.84 = 187.38/x
  3. Step 3: Cross multiply
    311.70x = 429.84 × 187.38
  4. Step 4: Simplify right side
    311.70x = 80,543.42
  5. Step 5: Solve for x
    x = 80,543.42/311.70
  6. Step 6: Final answer
    x = 258.40

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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.