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Finding the Fourth Proportional to 1,290, 1,780.22 and 700.55

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Solution

The fourth proportional to 1,290, 1,780.22 and 700.55 is: 966.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290 : 1,780.22 = 700.55 : x
  2. Step 2: Convert to fraction form
    1,290/1,780.22 = 700.55/x
  3. Step 3: Cross multiply
    1,290x = 1,780.22 × 700.55
  4. Step 4: Simplify right side
    1,290x = 1,247,120.72
  5. Step 5: Solve for x
    x = 1,247,120.72/1,290
  6. Step 6: Final answer
    x = 966.76

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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.