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Finding the Fourth Proportional to 283.20, 390.24 and 209.40

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Solution

The fourth proportional to 283.20, 390.24 and 209.40 is: 288.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    283.20 : 390.24 = 209.40 : x
  2. Step 2: Convert to fraction form
    283.20/390.24 = 209.40/x
  3. Step 3: Cross multiply
    283.20x = 390.24 × 209.40
  4. Step 4: Simplify right side
    283.20x = 81,716.26
  5. Step 5: Solve for x
    x = 81,716.26/283.20
  6. Step 6: Final answer
    x = 288.55

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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.