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Finding the Fourth Proportional to 200.40, 300.21 and 78.54

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Solution

The fourth proportional to 200.40, 300.21 and 78.54 is: 117.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    200.40 : 300.21 = 78.54 : x
  2. Step 2: Convert to fraction form
    200.40/300.21 = 78.54/x
  3. Step 3: Cross multiply
    200.40x = 300.21 × 78.54
  4. Step 4: Simplify right side
    200.40x = 23,578.49
  5. Step 5: Solve for x
    x = 23,578.49/200.40
  6. Step 6: Final answer
    x = 117.66

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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.