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Finding the Fourth Proportional to 386.28, 578.61 and 290.70

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Solution

The fourth proportional to 386.28, 578.61 and 290.70 is: 435.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.28 : 578.61 = 290.70 : x
  2. Step 2: Convert to fraction form
    386.28/578.61 = 290.70/x
  3. Step 3: Cross multiply
    386.28x = 578.61 × 290.70
  4. Step 4: Simplify right side
    386.28x = 168,201.93
  5. Step 5: Solve for x
    x = 168,201.93/386.28
  6. Step 6: Final answer
    x = 435.44

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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.