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Finding the Fourth Proportional to 206.45, 309.74 and 84.81

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Solution

The fourth proportional to 206.45, 309.74 and 84.81 is: 127.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.45 : 309.74 = 84.81 : x
  2. Step 2: Convert to fraction form
    206.45/309.74 = 84.81/x
  3. Step 3: Cross multiply
    206.45x = 309.74 × 84.81
  4. Step 4: Simplify right side
    206.45x = 26,268.63
  5. Step 5: Solve for x
    x = 26,268.63/206.45
  6. Step 6: Final answer
    x = 127.24

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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.