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Finding the Fourth Proportional to 386.20, 578.05 and 247.47

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Solution

The fourth proportional to 386.20, 578.05 and 247.47 is: 370.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.20 : 578.05 = 247.47 : x
  2. Step 2: Convert to fraction form
    386.20/578.05 = 247.47/x
  3. Step 3: Cross multiply
    386.20x = 578.05 × 247.47
  4. Step 4: Simplify right side
    386.20x = 143,047.25
  5. Step 5: Solve for x
    x = 143,047.25/386.20
  6. Step 6: Final answer
    x = 370.40

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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.