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Finding the Fourth Proportional to 287.39, 428.87 and 256.63

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Solution

The fourth proportional to 287.39, 428.87 and 256.63 is: 382.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.39 : 428.87 = 256.63 : x
  2. Step 2: Convert to fraction form
    287.39/428.87 = 256.63/x
  3. Step 3: Cross multiply
    287.39x = 428.87 × 256.63
  4. Step 4: Simplify right side
    287.39x = 110,058.55
  5. Step 5: Solve for x
    x = 110,058.55/287.39
  6. Step 6: Final answer
    x = 382.96

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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.