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Finding the Fourth Proportional to 998.92, 1,498.92 and 421.78

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Solution

The fourth proportional to 998.92, 1,498.92 and 421.78 is: 632.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.92 : 1,498.92 = 421.78 : x
  2. Step 2: Convert to fraction form
    998.92/1,498.92 = 421.78/x
  3. Step 3: Cross multiply
    998.92x = 1,498.92 × 421.78
  4. Step 4: Simplify right side
    998.92x = 632,214.48
  5. Step 5: Solve for x
    x = 632,214.48/998.92
  6. Step 6: Final answer
    x = 632.90

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1.5x scale

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.