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Finding the Fourth Proportional to 287.20, 428.90 and 250.75

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Solution

The fourth proportional to 287.20, 428.90 and 250.75 is: 374.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.20 : 428.90 = 250.75 : x
  2. Step 2: Convert to fraction form
    287.20/428.90 = 250.75/x
  3. Step 3: Cross multiply
    287.20x = 428.90 × 250.75
  4. Step 4: Simplify right side
    287.20x = 107,546.68
  5. Step 5: Solve for x
    x = 107,546.68/287.20
  6. Step 6: Final answer
    x = 374.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.