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Finding the Fourth Proportional to 305.28, 457.20 and 208.80

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Solution

The fourth proportional to 305.28, 457.20 and 208.80 is: 312.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.28 : 457.20 = 208.80 : x
  2. Step 2: Convert to fraction form
    305.28/457.20 = 208.80/x
  3. Step 3: Cross multiply
    305.28x = 457.20 × 208.80
  4. Step 4: Simplify right side
    305.28x = 95,463.36
  5. Step 5: Solve for x
    x = 95,463.36/305.28
  6. Step 6: Final answer
    x = 312.71

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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.