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Finding the Fourth Proportional to 307.15, 423.69 and 208.72

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Solution

The fourth proportional to 307.15, 423.69 and 208.72 is: 287.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    307.15 : 423.69 = 208.72 : x
  2. Step 2: Convert to fraction form
    307.15/423.69 = 208.72/x
  3. Step 3: Cross multiply
    307.15x = 423.69 × 208.72
  4. Step 4: Simplify right side
    307.15x = 88,432.58
  5. Step 5: Solve for x
    x = 88,432.58/307.15
  6. Step 6: Final answer
    x = 287.91

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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.