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Finding the Fourth Proportional to 386.42, 578.91 and 191.20

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Solution

The fourth proportional to 386.42, 578.91 and 191.20 is: 286.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.42 : 578.91 = 191.20 : x
  2. Step 2: Convert to fraction form
    386.42/578.91 = 191.20/x
  3. Step 3: Cross multiply
    386.42x = 578.91 × 191.20
  4. Step 4: Simplify right side
    386.42x = 110,684.70
  5. Step 5: Solve for x
    x = 110,684.70/386.42
  6. Step 6: Final answer
    x = 286.43

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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.