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Finding the Fourth Proportional to 206.50, 309.80 and 69.51

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Solution

The fourth proportional to 206.50, 309.80 and 69.51 is: 104.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.50 : 309.80 = 69.51 : x
  2. Step 2: Convert to fraction form
    206.50/309.80 = 69.51/x
  3. Step 3: Cross multiply
    206.50x = 309.80 × 69.51
  4. Step 4: Simplify right side
    206.50x = 21,534.20
  5. Step 5: Solve for x
    x = 21,534.20/206.50
  6. Step 6: Final answer
    x = 104.28

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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.