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Finding the Fourth Proportional to 289.64, 399.72 and 196.40

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Solution

The fourth proportional to 289.64, 399.72 and 196.40 is: 271.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.64 : 399.72 = 196.40 : x
  2. Step 2: Convert to fraction form
    289.64/399.72 = 196.40/x
  3. Step 3: Cross multiply
    289.64x = 399.72 × 196.40
  4. Step 4: Simplify right side
    289.64x = 78,505.01
  5. Step 5: Solve for x
    x = 78,505.01/289.64
  6. Step 6: Final answer
    x = 271.04

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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.