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Finding the Fourth Proportional to 306.78, 422.70 and 208.37

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Solution

The fourth proportional to 306.78, 422.70 and 208.37 is: 287.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.78 : 422.70 = 208.37 : x
  2. Step 2: Convert to fraction form
    306.78/422.70 = 208.37/x
  3. Step 3: Cross multiply
    306.78x = 422.70 × 208.37
  4. Step 4: Simplify right side
    306.78x = 88,075.10
  5. Step 5: Solve for x
    x = 88,075.10/306.78
  6. Step 6: Final answer
    x = 287.10

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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.