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Finding the Fourth Proportional to 3,138, 4,707 and 1,290.12

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Solution

The fourth proportional to 3,138, 4,707 and 1,290.12 is: 1,935.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,138 : 4,707 = 1,290.12 : x
  2. Step 2: Convert to fraction form
    3,138/4,707 = 1,290.12/x
  3. Step 3: Cross multiply
    3,138x = 4,707 × 1,290.12
  4. Step 4: Simplify right side
    3,138x = 6,072,594.84
  5. Step 5: Solve for x
    x = 6,072,594.84/3,138
  6. Step 6: Final answer
    x = 1,935.18

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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.