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Finding the Fourth Proportional to 998.84, 1,378.35 and 620.63

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Solution

The fourth proportional to 998.84, 1,378.35 and 620.63 is: 856.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.84 : 1,378.35 = 620.63 : x
  2. Step 2: Convert to fraction form
    998.84/1,378.35 = 620.63/x
  3. Step 3: Cross multiply
    998.84x = 1,378.35 × 620.63
  4. Step 4: Simplify right side
    998.84x = 855,445.36
  5. Step 5: Solve for x
    x = 855,445.36/998.84
  6. Step 6: Final answer
    x = 856.44

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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.