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Finding the Fourth Proportional to 789.89, 1,089.41 and 494.78

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Solution

The fourth proportional to 789.89, 1,089.41 and 494.78 is: 682.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.89 : 1,089.41 = 494.78 : x
  2. Step 2: Convert to fraction form
    789.89/1,089.41 = 494.78/x
  3. Step 3: Cross multiply
    789.89x = 1,089.41 × 494.78
  4. Step 4: Simplify right side
    789.89x = 539,018.53
  5. Step 5: Solve for x
    x = 539,018.53/789.89
  6. Step 6: Final answer
    x = 682.39

Related Problems

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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.