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Finding the Fourth Proportional to 902.09, 1,245.47 and 639.65

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Solution

The fourth proportional to 902.09, 1,245.47 and 639.65 is: 883.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    902.09 : 1,245.47 = 639.65 : x
  2. Step 2: Convert to fraction form
    902.09/1,245.47 = 639.65/x
  3. Step 3: Cross multiply
    902.09x = 1,245.47 × 639.65
  4. Step 4: Simplify right side
    902.09x = 796,655.46
  5. Step 5: Solve for x
    x = 796,655.46/902.09
  6. Step 6: Final answer
    x = 883.13

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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.