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Finding the Fourth Proportional to 291.80, 402.78 and 208.95

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Solution

The fourth proportional to 291.80, 402.78 and 208.95 is: 288.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.80 : 402.78 = 208.95 : x
  2. Step 2: Convert to fraction form
    291.80/402.78 = 208.95/x
  3. Step 3: Cross multiply
    291.80x = 402.78 × 208.95
  4. Step 4: Simplify right side
    291.80x = 84,160.88
  5. Step 5: Solve for x
    x = 84,160.88/291.80
  6. Step 6: Final answer
    x = 288.42

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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.