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Finding the Fourth Proportional to 842.90, 1,264.38 and 380.60

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Solution

The fourth proportional to 842.90, 1,264.38 and 380.60 is: 570.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.90 : 1,264.38 = 380.60 : x
  2. Step 2: Convert to fraction form
    842.90/1,264.38 = 380.60/x
  3. Step 3: Cross multiply
    842.90x = 1,264.38 × 380.60
  4. Step 4: Simplify right side
    842.90x = 481,223.03
  5. Step 5: Solve for x
    x = 481,223.03/842.90
  6. Step 6: Final answer
    x = 570.91

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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.