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Finding the Fourth Proportional to 1,245.81, 1,869 and 380.19

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Solution

The fourth proportional to 1,245.81, 1,869 and 380.19 is: 570.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,245.81 : 1,869 = 380.19 : x
  2. Step 2: Convert to fraction form
    1,245.81/1,869 = 380.19/x
  3. Step 3: Cross multiply
    1,245.81x = 1,869 × 380.19
  4. Step 4: Simplify right side
    1,245.81x = 710,575.11
  5. Step 5: Solve for x
    x = 710,575.11/1,245.81
  6. Step 6: Final answer
    x = 570.37

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Double scale
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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.