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Finding the Fourth Proportional to 209.21, 311.87 and 180.45

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Solution

The fourth proportional to 209.21, 311.87 and 180.45 is: 269.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.21 : 311.87 = 180.45 : x
  2. Step 2: Convert to fraction form
    209.21/311.87 = 180.45/x
  3. Step 3: Cross multiply
    209.21x = 311.87 × 180.45
  4. Step 4: Simplify right side
    209.21x = 56,277.39
  5. Step 5: Solve for x
    x = 56,277.39/209.21
  6. Step 6: Final answer
    x = 269.01

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.