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Finding the Fourth Proportional to 780.66, 1,169.19 and 455.40

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Solution

The fourth proportional to 780.66, 1,169.19 and 455.40 is: 682.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.66 : 1,169.19 = 455.40 : x
  2. Step 2: Convert to fraction form
    780.66/1,169.19 = 455.40/x
  3. Step 3: Cross multiply
    780.66x = 1,169.19 × 455.40
  4. Step 4: Simplify right side
    780.66x = 532,449.13
  5. Step 5: Solve for x
    x = 532,449.13/780.66
  6. Step 6: Final answer
    x = 682.05

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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.