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Finding the Fourth Proportional to 863.40, 1,193.22 and 643.08

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Solution

The fourth proportional to 863.40, 1,193.22 and 643.08 is: 888.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.40 : 1,193.22 = 643.08 : x
  2. Step 2: Convert to fraction form
    863.40/1,193.22 = 643.08/x
  3. Step 3: Cross multiply
    863.40x = 1,193.22 × 643.08
  4. Step 4: Simplify right side
    863.40x = 767,335.92
  5. Step 5: Solve for x
    x = 767,335.92/863.40
  6. Step 6: Final answer
    x = 888.74

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Double scale
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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.