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Finding the Fourth Proportional to 911.40, 1,367.55 and 521.70

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Solution

The fourth proportional to 911.40, 1,367.55 and 521.70 is: 782.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.40 : 1,367.55 = 521.70 : x
  2. Step 2: Convert to fraction form
    911.40/1,367.55 = 521.70/x
  3. Step 3: Cross multiply
    911.40x = 1,367.55 × 521.70
  4. Step 4: Simplify right side
    911.40x = 713,450.84
  5. Step 5: Solve for x
    x = 713,450.84/911.40
  6. Step 6: Final answer
    x = 782.81

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.