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Finding the Fourth Proportional to 1,387.40, 2,081.10 and 1,379.30

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Solution

The fourth proportional to 1,387.40, 2,081.10 and 1,379.30 is: 2,068.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,387.40 : 2,081.10 = 1,379.30 : x
  2. Step 2: Convert to fraction form
    1,387.40/2,081.10 = 1,379.30/x
  3. Step 3: Cross multiply
    1,387.40x = 2,081.10 × 1,379.30
  4. Step 4: Simplify right side
    1,387.40x = 2,870,461.23
  5. Step 5: Solve for x
    x = 2,870,461.23/1,387.40
  6. Step 6: Final answer
    x = 2,068.95

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1.5x scale

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.