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Finding the Fourth Proportional to 1,679.40, 2,518.43 and 639.05

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Solution

The fourth proportional to 1,679.40, 2,518.43 and 639.05 is: 958.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,679.40 : 2,518.43 = 639.05 : x
  2. Step 2: Convert to fraction form
    1,679.40/2,518.43 = 639.05/x
  3. Step 3: Cross multiply
    1,679.40x = 2,518.43 × 639.05
  4. Step 4: Simplify right side
    1,679.40x = 1,609,386.90
  5. Step 5: Solve for x
    x = 1,609,386.90/1,679.40
  6. Step 6: Final answer
    x = 958.31

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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.