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Finding the Fourth Proportional to 891.58, 1,228.62 and 642.46

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Solution

The fourth proportional to 891.58, 1,228.62 and 642.46 is: 885.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.58 : 1,228.62 = 642.46 : x
  2. Step 2: Convert to fraction form
    891.58/1,228.62 = 642.46/x
  3. Step 3: Cross multiply
    891.58x = 1,228.62 × 642.46
  4. Step 4: Simplify right side
    891.58x = 789,339.21
  5. Step 5: Solve for x
    x = 789,339.21/891.58
  6. Step 6: Final answer
    x = 885.33

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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.