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Finding the Fourth Proportional to 218.69, 301.78 and 120.45

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Solution

The fourth proportional to 218.69, 301.78 and 120.45 is: 166.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.69 : 301.78 = 120.45 : x
  2. Step 2: Convert to fraction form
    218.69/301.78 = 120.45/x
  3. Step 3: Cross multiply
    218.69x = 301.78 × 120.45
  4. Step 4: Simplify right side
    218.69x = 36,349.40
  5. Step 5: Solve for x
    x = 36,349.40/218.69
  6. Step 6: Final answer
    x = 166.21

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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.