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Finding the Fourth Proportional to 311.60, 429.96 and 278.96

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Solution

The fourth proportional to 311.60, 429.96 and 278.96 is: 384.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.60 : 429.96 = 278.96 : x
  2. Step 2: Convert to fraction form
    311.60/429.96 = 278.96/x
  3. Step 3: Cross multiply
    311.60x = 429.96 × 278.96
  4. Step 4: Simplify right side
    311.60x = 119,941.64
  5. Step 5: Solve for x
    x = 119,941.64/311.60
  6. Step 6: Final answer
    x = 384.92

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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.