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Finding the Fourth Proportional to 2,319.12, 3,479.04 and 780

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Solution

The fourth proportional to 2,319.12, 3,479.04 and 780 is: 1,170.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,319.12 : 3,479.04 = 780 : x
  2. Step 2: Convert to fraction form
    2,319.12/3,479.04 = 780/x
  3. Step 3: Cross multiply
    2,319.12x = 3,479.04 × 780
  4. Step 4: Simplify right side
    2,319.12x = 2,713,651.20
  5. Step 5: Solve for x
    x = 2,713,651.20/2,319.12
  6. Step 6: Final answer
    x = 1,170.12

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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.