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Finding the Fourth Proportional to 639.40, 957.22 and 485.93

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Solution

The fourth proportional to 639.40, 957.22 and 485.93 is: 727.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.40 : 957.22 = 485.93 : x
  2. Step 2: Convert to fraction form
    639.40/957.22 = 485.93/x
  3. Step 3: Cross multiply
    639.40x = 957.22 × 485.93
  4. Step 4: Simplify right side
    639.40x = 465,141.91
  5. Step 5: Solve for x
    x = 465,141.91/639.40
  6. Step 6: Final answer
    x = 727.47

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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.