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Finding the Fourth Proportional to 998.88, 1,378.40 and 579.20

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Solution

The fourth proportional to 998.88, 1,378.40 and 579.20 is: 799.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.88 : 1,378.40 = 579.20 : x
  2. Step 2: Convert to fraction form
    998.88/1,378.40 = 579.20/x
  3. Step 3: Cross multiply
    998.88x = 1,378.40 × 579.20
  4. Step 4: Simplify right side
    998.88x = 798,369.83
  5. Step 5: Solve for x
    x = 798,369.83/998.88
  6. Step 6: Final answer
    x = 799.27

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.