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Finding the Fourth Proportional to 1,642.20, 2,266.44 and 978.72

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Solution

The fourth proportional to 1,642.20, 2,266.44 and 978.72 is: 1,350.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,642.20 : 2,266.44 = 978.72 : x
  2. Step 2: Convert to fraction form
    1,642.20/2,266.44 = 978.72/x
  3. Step 3: Cross multiply
    1,642.20x = 2,266.44 × 978.72
  4. Step 4: Simplify right side
    1,642.20x = 2,218,210.16
  5. Step 5: Solve for x
    x = 2,218,210.16/1,642.20
  6. Step 6: Final answer
    x = 1,350.76

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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.