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Finding the Fourth Proportional to 305.28, 457.45 and 142.78

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Solution

The fourth proportional to 305.28, 457.45 and 142.78 is: 213.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.28 : 457.45 = 142.78 : x
  2. Step 2: Convert to fraction form
    305.28/457.45 = 142.78/x
  3. Step 3: Cross multiply
    305.28x = 457.45 × 142.78
  4. Step 4: Simplify right side
    305.28x = 65,314.71
  5. Step 5: Solve for x
    x = 65,314.71/305.28
  6. Step 6: Final answer
    x = 213.95

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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.