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Finding the Fourth Proportional to 1,812.80, 2,718.40 and 839.20

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Solution

The fourth proportional to 1,812.80, 2,718.40 and 839.20 is: 1,258.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,812.80 : 2,718.40 = 839.20 : x
  2. Step 2: Convert to fraction form
    1,812.80/2,718.40 = 839.20/x
  3. Step 3: Cross multiply
    1,812.80x = 2,718.40 × 839.20
  4. Step 4: Simplify right side
    1,812.80x = 2,281,281.28
  5. Step 5: Solve for x
    x = 2,281,281.28/1,812.80
  6. Step 6: Final answer
    x = 1,258.43

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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.