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Finding the Fourth Proportional to 1,871.85, 2,808.21 and 639.27

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Solution

The fourth proportional to 1,871.85, 2,808.21 and 639.27 is: 959.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,871.85 : 2,808.21 = 639.27 : x
  2. Step 2: Convert to fraction form
    1,871.85/2,808.21 = 639.27/x
  3. Step 3: Cross multiply
    1,871.85x = 2,808.21 × 639.27
  4. Step 4: Simplify right side
    1,871.85x = 1,795,204.41
  5. Step 5: Solve for x
    x = 1,795,204.41/1,871.85
  6. Step 6: Final answer
    x = 959.05

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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.