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Finding the Fourth Proportional to 1,369.81, 2,053.29 and 638.78

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Solution

The fourth proportional to 1,369.81, 2,053.29 and 638.78 is: 957.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,369.81 : 2,053.29 = 638.78 : x
  2. Step 2: Convert to fraction form
    1,369.81/2,053.29 = 638.78/x
  3. Step 3: Cross multiply
    1,369.81x = 2,053.29 × 638.78
  4. Step 4: Simplify right side
    1,369.81x = 1,311,600.59
  5. Step 5: Solve for x
    x = 1,311,600.59/1,369.81
  6. Step 6: Final answer
    x = 957.51

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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.