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Finding the Fourth Proportional to 289.56, 399.90 and 287.54

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Solution

The fourth proportional to 289.56, 399.90 and 287.54 is: 397.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.56 : 399.90 = 287.54 : x
  2. Step 2: Convert to fraction form
    289.56/399.90 = 287.54/x
  3. Step 3: Cross multiply
    289.56x = 399.90 × 287.54
  4. Step 4: Simplify right side
    289.56x = 114,987.25
  5. Step 5: Solve for x
    x = 114,987.25/289.56
  6. Step 6: Final answer
    x = 397.11

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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.