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Finding the Fourth Proportional to 863.68, 1,190.28 and 642.28

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Solution

The fourth proportional to 863.68, 1,190.28 and 642.28 is: 885.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.68 : 1,190.28 = 642.28 : x
  2. Step 2: Convert to fraction form
    863.68/1,190.28 = 642.28/x
  3. Step 3: Cross multiply
    863.68x = 1,190.28 × 642.28
  4. Step 4: Simplify right side
    863.68x = 764,493.04
  5. Step 5: Solve for x
    x = 764,493.04/863.68
  6. Step 6: Final answer
    x = 885.16

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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.