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Finding the Fourth Proportional to 858.78, 1,288.22 and 209.52

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Solution

The fourth proportional to 858.78, 1,288.22 and 209.52 is: 314.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.78 : 1,288.22 = 209.52 : x
  2. Step 2: Convert to fraction form
    858.78/1,288.22 = 209.52/x
  3. Step 3: Cross multiply
    858.78x = 1,288.22 × 209.52
  4. Step 4: Simplify right side
    858.78x = 269,906.81
  5. Step 5: Solve for x
    x = 269,906.81/858.78
  6. Step 6: Final answer
    x = 314.29

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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.