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Finding the Fourth Proportional to 289.71, 399.78 and 165.39

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Solution

The fourth proportional to 289.71, 399.78 and 165.39 is: 228.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.71 : 399.78 = 165.39 : x
  2. Step 2: Convert to fraction form
    289.71/399.78 = 165.39/x
  3. Step 3: Cross multiply
    289.71x = 399.78 × 165.39
  4. Step 4: Simplify right side
    289.71x = 66,119.61
  5. Step 5: Solve for x
    x = 66,119.61/289.71
  6. Step 6: Final answer
    x = 228.23

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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.