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Finding the Fourth Proportional to 1,079.62, 1,618.48 and 639.79

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Solution

The fourth proportional to 1,079.62, 1,618.48 and 639.79 is: 959.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,079.62 : 1,618.48 = 639.79 : x
  2. Step 2: Convert to fraction form
    1,079.62/1,618.48 = 639.79/x
  3. Step 3: Cross multiply
    1,079.62x = 1,618.48 × 639.79
  4. Step 4: Simplify right side
    1,079.62x = 1,035,488.62
  5. Step 5: Solve for x
    x = 1,035,488.62/1,079.62
  6. Step 6: Final answer
    x = 959.12

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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.