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Finding the Fourth Proportional to 163.80, 245.55 and 86.71

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Solution

The fourth proportional to 163.80, 245.55 and 86.71 is: 129.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    163.80 : 245.55 = 86.71 : x
  2. Step 2: Convert to fraction form
    163.80/245.55 = 86.71/x
  3. Step 3: Cross multiply
    163.80x = 245.55 × 86.71
  4. Step 4: Simplify right side
    163.80x = 21,291.64
  5. Step 5: Solve for x
    x = 21,291.64/163.80
  6. Step 6: Final answer
    x = 129.99

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.