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Finding the Fourth Proportional to 311.84, 429.36 and 256.40

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Solution

The fourth proportional to 311.84, 429.36 and 256.40 is: 353.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.84 : 429.36 = 256.40 : x
  2. Step 2: Convert to fraction form
    311.84/429.36 = 256.40/x
  3. Step 3: Cross multiply
    311.84x = 429.36 × 256.40
  4. Step 4: Simplify right side
    311.84x = 110,087.90
  5. Step 5: Solve for x
    x = 110,087.90/311.84
  6. Step 6: Final answer
    x = 353.03

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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.