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Finding the Fourth Proportional to 998.80, 1,378.34 and 556.74

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Solution

The fourth proportional to 998.80, 1,378.34 and 556.74 is: 768.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.80 : 1,378.34 = 556.74 : x
  2. Step 2: Convert to fraction form
    998.80/1,378.34 = 556.74/x
  3. Step 3: Cross multiply
    998.80x = 1,378.34 × 556.74
  4. Step 4: Simplify right side
    998.80x = 767,377.01
  5. Step 5: Solve for x
    x = 767,377.01/998.80
  6. Step 6: Final answer
    x = 768.30

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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.