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Finding the Fourth Proportional to 209.28, 309.60 and 209.28

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Solution

The fourth proportional to 209.28, 309.60 and 209.28 is: 309.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.28 : 309.60 = 209.28 : x
  2. Step 2: Convert to fraction form
    209.28/309.60 = 209.28/x
  3. Step 3: Cross multiply
    209.28x = 309.60 × 209.28
  4. Step 4: Simplify right side
    209.28x = 64,793.09
  5. Step 5: Solve for x
    x = 64,793.09/209.28
  6. Step 6: Final answer
    x = 309.60

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.