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Finding the Fourth Proportional to 208.79, 288.14 and 115.55

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Solution

The fourth proportional to 208.79, 288.14 and 115.55 is: 159.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.79 : 288.14 = 115.55 : x
  2. Step 2: Convert to fraction form
    208.79/288.14 = 115.55/x
  3. Step 3: Cross multiply
    208.79x = 288.14 × 115.55
  4. Step 4: Simplify right side
    208.79x = 33,292.56
  5. Step 5: Solve for x
    x = 33,292.56/208.79
  6. Step 6: Final answer
    x = 159.45

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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.