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Finding the Fourth Proportional to 311.55, 427.64 and 283.76

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Solution

The fourth proportional to 311.55, 427.64 and 283.76 is: 389.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.55 : 427.64 = 283.76 : x
  2. Step 2: Convert to fraction form
    311.55/427.64 = 283.76/x
  3. Step 3: Cross multiply
    311.55x = 427.64 × 283.76
  4. Step 4: Simplify right side
    311.55x = 121,343.57
  5. Step 5: Solve for x
    x = 121,343.57/311.55
  6. Step 6: Final answer
    x = 389.48

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.