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Finding the Fourth Proportional to 289.09, 399.30 and 287.07

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Solution

The fourth proportional to 289.09, 399.30 and 287.07 is: 396.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.09 : 399.30 = 287.07 : x
  2. Step 2: Convert to fraction form
    289.09/399.30 = 287.07/x
  3. Step 3: Cross multiply
    289.09x = 399.30 × 287.07
  4. Step 4: Simplify right side
    289.09x = 114,624.48
  5. Step 5: Solve for x
    x = 114,624.48/289.09
  6. Step 6: Final answer
    x = 396.50

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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.