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Finding the Fourth Proportional to 990.26, 1,366.29 and 641.30

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Solution

The fourth proportional to 990.26, 1,366.29 and 641.30 is: 884.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.26 : 1,366.29 = 641.30 : x
  2. Step 2: Convert to fraction form
    990.26/1,366.29 = 641.30/x
  3. Step 3: Cross multiply
    990.26x = 1,366.29 × 641.30
  4. Step 4: Simplify right side
    990.26x = 876,201.78
  5. Step 5: Solve for x
    x = 876,201.78/990.26
  6. Step 6: Final answer
    x = 884.82

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1.5x scale

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.