Home / 1,211.50-1,817.40-389.68

Finding the Fourth Proportional to 1,211.50, 1,817.40 and 389.68

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Solution

The fourth proportional to 1,211.50, 1,817.40 and 389.68 is: 584.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,211.50 : 1,817.40 = 389.68 : x
  2. Step 2: Convert to fraction form
    1,211.50/1,817.40 = 389.68/x
  3. Step 3: Cross multiply
    1,211.50x = 1,817.40 × 389.68
  4. Step 4: Simplify right side
    1,211.50x = 708,204.43
  5. Step 5: Solve for x
    x = 708,204.43/1,211.50
  6. Step 6: Final answer
    x = 584.57

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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.