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Finding the Fourth Proportional to 289.40, 399.10 and 205.43

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Solution

The fourth proportional to 289.40, 399.10 and 205.43 is: 283.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.40 : 399.10 = 205.43 : x
  2. Step 2: Convert to fraction form
    289.40/399.10 = 205.43/x
  3. Step 3: Cross multiply
    289.40x = 399.10 × 205.43
  4. Step 4: Simplify right side
    289.40x = 81,987.11
  5. Step 5: Solve for x
    x = 81,987.11/289.40
  6. Step 6: Final answer
    x = 283.30

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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.