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Finding the Fourth Proportional to 208.79, 288.05 and 135.15

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Solution

The fourth proportional to 208.79, 288.05 and 135.15 is: 186.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.79 : 288.05 = 135.15 : x
  2. Step 2: Convert to fraction form
    208.79/288.05 = 135.15/x
  3. Step 3: Cross multiply
    208.79x = 288.05 × 135.15
  4. Step 4: Simplify right side
    208.79x = 38,929.96
  5. Step 5: Solve for x
    x = 38,929.96/208.79
  6. Step 6: Final answer
    x = 186.46

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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.