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Finding the Fourth Proportional to 639.04, 957.04 and 407.20

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Solution

The fourth proportional to 639.04, 957.04 and 407.20 is: 609.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.04 : 957.04 = 407.20 : x
  2. Step 2: Convert to fraction form
    639.04/957.04 = 407.20/x
  3. Step 3: Cross multiply
    639.04x = 957.04 × 407.20
  4. Step 4: Simplify right side
    639.04x = 389,706.69
  5. Step 5: Solve for x
    x = 389,706.69/639.04
  6. Step 6: Final answer
    x = 609.83

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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.