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Finding the Fourth Proportional to 789.63, 1,087.87 and 623.78

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Solution

The fourth proportional to 789.63, 1,087.87 and 623.78 is: 859.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.63 : 1,087.87 = 623.78 : x
  2. Step 2: Convert to fraction form
    789.63/1,087.87 = 623.78/x
  3. Step 3: Cross multiply
    789.63x = 1,087.87 × 623.78
  4. Step 4: Simplify right side
    789.63x = 678,591.55
  5. Step 5: Solve for x
    x = 678,591.55/789.63
  6. Step 6: Final answer
    x = 859.38

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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.