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Finding the Fourth Proportional to 289.40, 399.40 and 240.20

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Solution

The fourth proportional to 289.40, 399.40 and 240.20 is: 331.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.40 : 399.40 = 240.20 : x
  2. Step 2: Convert to fraction form
    289.40/399.40 = 240.20/x
  3. Step 3: Cross multiply
    289.40x = 399.40 × 240.20
  4. Step 4: Simplify right side
    289.40x = 95,935.88
  5. Step 5: Solve for x
    x = 95,935.88/289.40
  6. Step 6: Final answer
    x = 331.50

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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.