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Finding the Fourth Proportional to 858.91, 1,288.35 and 209.63

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Solution

The fourth proportional to 858.91, 1,288.35 and 209.63 is: 314.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.91 : 1,288.35 = 209.63 : x
  2. Step 2: Convert to fraction form
    858.91/1,288.35 = 209.63/x
  3. Step 3: Cross multiply
    858.91x = 1,288.35 × 209.63
  4. Step 4: Simplify right side
    858.91x = 270,076.81
  5. Step 5: Solve for x
    x = 270,076.81/858.91
  6. Step 6: Final answer
    x = 314.44

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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.