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Finding the Fourth Proportional to 825, 1,236.88 and 643.35

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Solution

The fourth proportional to 825, 1,236.88 and 643.35 is: 964.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    825 : 1,236.88 = 643.35 : x
  2. Step 2: Convert to fraction form
    825/1,236.88 = 643.35/x
  3. Step 3: Cross multiply
    825x = 1,236.88 × 643.35
  4. Step 4: Simplify right side
    825x = 795,746.75
  5. Step 5: Solve for x
    x = 795,746.75/825
  6. Step 6: Final answer
    x = 964.54

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.