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Finding the Fourth Proportional to 890.20, 1,335.30 and 839.80

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Solution

The fourth proportional to 890.20, 1,335.30 and 839.80 is: 1,259.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.20 : 1,335.30 = 839.80 : x
  2. Step 2: Convert to fraction form
    890.20/1,335.30 = 839.80/x
  3. Step 3: Cross multiply
    890.20x = 1,335.30 × 839.80
  4. Step 4: Simplify right side
    890.20x = 1,121,384.94
  5. Step 5: Solve for x
    x = 1,121,384.94/890.20
  6. Step 6: Final answer
    x = 1,259.70

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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.