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Finding the Fourth Proportional to 789.08, 1,085.81 and 678.11

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Solution

The fourth proportional to 789.08, 1,085.81 and 678.11 is: 933.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.08 : 1,085.81 = 678.11 : x
  2. Step 2: Convert to fraction form
    789.08/1,085.81 = 678.11/x
  3. Step 3: Cross multiply
    789.08x = 1,085.81 × 678.11
  4. Step 4: Simplify right side
    789.08x = 736,289.80
  5. Step 5: Solve for x
    x = 736,289.80/789.08
  6. Step 6: Final answer
    x = 933.10

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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.