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Finding the Fourth Proportional to 969.93, 1,338.21 and 638.55

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Solution

The fourth proportional to 969.93, 1,338.21 and 638.55 is: 881.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    969.93 : 1,338.21 = 638.55 : x
  2. Step 2: Convert to fraction form
    969.93/1,338.21 = 638.55/x
  3. Step 3: Cross multiply
    969.93x = 1,338.21 × 638.55
  4. Step 4: Simplify right side
    969.93x = 854,514.00
  5. Step 5: Solve for x
    x = 854,514.00/969.93
  6. Step 6: Final answer
    x = 881.01

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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.