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Finding the Fourth Proportional to 307.80, 424.34 and 209.39

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Solution

The fourth proportional to 307.80, 424.34 and 209.39 is: 288.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    307.80 : 424.34 = 209.39 : x
  2. Step 2: Convert to fraction form
    307.80/424.34 = 209.39/x
  3. Step 3: Cross multiply
    307.80x = 424.34 × 209.39
  4. Step 4: Simplify right side
    307.80x = 88,850.17
  5. Step 5: Solve for x
    x = 88,850.17/307.80
  6. Step 6: Final answer
    x = 288.66

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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.