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Finding the Fourth Proportional to 36.90, 50.85 and 30.78

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Solution

The fourth proportional to 36.90, 50.85 and 30.78 is: 42.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    36.90 : 50.85 = 30.78 : x
  2. Step 2: Convert to fraction form
    36.90/50.85 = 30.78/x
  3. Step 3: Cross multiply
    36.90x = 50.85 × 30.78
  4. Step 4: Simplify right side
    36.90x = 1,565.16
  5. Step 5: Solve for x
    x = 1,565.16/36.90
  6. Step 6: Final answer
    x = 42.42

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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.