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Finding the Fourth Proportional to 201.78, 302.45 and 78.38

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Solution

The fourth proportional to 201.78, 302.45 and 78.38 is: 117.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    201.78 : 302.45 = 78.38 : x
  2. Step 2: Convert to fraction form
    201.78/302.45 = 78.38/x
  3. Step 3: Cross multiply
    201.78x = 302.45 × 78.38
  4. Step 4: Simplify right side
    201.78x = 23,704.13
  5. Step 5: Solve for x
    x = 23,704.13/201.78
  6. Step 6: Final answer
    x = 117.48

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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.