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Finding the Fourth Proportional to 1,379.35, 2,070.05 and 860.11

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Solution

The fourth proportional to 1,379.35, 2,070.05 and 860.11 is: 1,290.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.35 : 2,070.05 = 860.11 : x
  2. Step 2: Convert to fraction form
    1,379.35/2,070.05 = 860.11/x
  3. Step 3: Cross multiply
    1,379.35x = 2,070.05 × 860.11
  4. Step 4: Simplify right side
    1,379.35x = 1,780,470.71
  5. Step 5: Solve for x
    x = 1,780,470.71/1,379.35
  6. Step 6: Final answer
    x = 1,290.80

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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.