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Finding the Fourth Proportional to 969.89, 1,338.65 and 638.34

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Solution

The fourth proportional to 969.89, 1,338.65 and 638.34 is: 881.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    969.89 : 1,338.65 = 638.34 : x
  2. Step 2: Convert to fraction form
    969.89/1,338.65 = 638.34/x
  3. Step 3: Cross multiply
    969.89x = 1,338.65 × 638.34
  4. Step 4: Simplify right side
    969.89x = 854,515.44
  5. Step 5: Solve for x
    x = 854,515.44/969.89
  6. Step 6: Final answer
    x = 881.05

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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.