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Finding the Fourth Proportional to 287.06, 430.28 and 208.78

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Solution

The fourth proportional to 287.06, 430.28 and 208.78 is: 312.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.06 : 430.28 = 208.78 : x
  2. Step 2: Convert to fraction form
    287.06/430.28 = 208.78/x
  3. Step 3: Cross multiply
    287.06x = 430.28 × 208.78
  4. Step 4: Simplify right side
    287.06x = 89,833.86
  5. Step 5: Solve for x
    x = 89,833.86/287.06
  6. Step 6: Final answer
    x = 312.94

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.