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Finding the Fourth Proportional to 1,338.65, 2,008.28 and 645.90

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Solution

The fourth proportional to 1,338.65, 2,008.28 and 645.90 is: 969.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,338.65 : 2,008.28 = 645.90 : x
  2. Step 2: Convert to fraction form
    1,338.65/2,008.28 = 645.90/x
  3. Step 3: Cross multiply
    1,338.65x = 2,008.28 × 645.90
  4. Step 4: Simplify right side
    1,338.65x = 1,297,155.99
  5. Step 5: Solve for x
    x = 1,297,155.99/1,338.65
  6. Step 6: Final answer
    x = 969.00

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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.