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Finding the Fourth Proportional to 290.80, 400.20 and 283.60

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Solution

The fourth proportional to 290.80, 400.20 and 283.60 is: 390.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.80 : 400.20 = 283.60 : x
  2. Step 2: Convert to fraction form
    290.80/400.20 = 283.60/x
  3. Step 3: Cross multiply
    290.80x = 400.20 × 283.60
  4. Step 4: Simplify right side
    290.80x = 113,496.72
  5. Step 5: Solve for x
    x = 113,496.72/290.80
  6. Step 6: Final answer
    x = 390.29

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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.