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Finding the Fourth Proportional to 2,780, 3,836.40 and 1,538.08

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Solution

The fourth proportional to 2,780, 3,836.40 and 1,538.08 is: 2,122.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,780 : 3,836.40 = 1,538.08 : x
  2. Step 2: Convert to fraction form
    2,780/3,836.40 = 1,538.08/x
  3. Step 3: Cross multiply
    2,780x = 3,836.40 × 1,538.08
  4. Step 4: Simplify right side
    2,780x = 5,900,690.11
  5. Step 5: Solve for x
    x = 5,900,690.11/2,780
  6. Step 6: Final answer
    x = 2,122.55

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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.