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Finding the Fourth Proportional to 309.81, 427.61 and 210.39

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Solution

The fourth proportional to 309.81, 427.61 and 210.39 is: 290.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.81 : 427.61 = 210.39 : x
  2. Step 2: Convert to fraction form
    309.81/427.61 = 210.39/x
  3. Step 3: Cross multiply
    309.81x = 427.61 × 210.39
  4. Step 4: Simplify right side
    309.81x = 89,964.33
  5. Step 5: Solve for x
    x = 89,964.33/309.81
  6. Step 6: Final answer
    x = 290.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.