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Finding the Fourth Proportional to 891.10, 1,228.26 and 642.07

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Solution

The fourth proportional to 891.10, 1,228.26 and 642.07 is: 885.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.10 : 1,228.26 = 642.07 : x
  2. Step 2: Convert to fraction form
    891.10/1,228.26 = 642.07/x
  3. Step 3: Cross multiply
    891.10x = 1,228.26 × 642.07
  4. Step 4: Simplify right side
    891.10x = 788,628.90
  5. Step 5: Solve for x
    x = 788,628.90/891.10
  6. Step 6: Final answer
    x = 885.01

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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.