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Finding the Fourth Proportional to 311.56, 430.02 and 208

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Solution

The fourth proportional to 311.56, 430.02 and 208 is: 287.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.56 : 430.02 = 208 : x
  2. Step 2: Convert to fraction form
    311.56/430.02 = 208/x
  3. Step 3: Cross multiply
    311.56x = 430.02 × 208
  4. Step 4: Simplify right side
    311.56x = 89,444.16
  5. Step 5: Solve for x
    x = 89,444.16/311.56
  6. Step 6: Final answer
    x = 287.08

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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.