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Finding the Fourth Proportional to 857.79, 1,286.62 and 272.81

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Solution

The fourth proportional to 857.79, 1,286.62 and 272.81 is: 409.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.79 : 1,286.62 = 272.81 : x
  2. Step 2: Convert to fraction form
    857.79/1,286.62 = 272.81/x
  3. Step 3: Cross multiply
    857.79x = 1,286.62 × 272.81
  4. Step 4: Simplify right side
    857.79x = 351,005.34
  5. Step 5: Solve for x
    x = 351,005.34/857.79
  6. Step 6: Final answer
    x = 409.20

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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.