Home / 1,211.90-1,818.16-390.16

Finding the Fourth Proportional to 1,211.90, 1,818.16 and 390.16

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Solution

The fourth proportional to 1,211.90, 1,818.16 and 390.16 is: 585.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,211.90 : 1,818.16 = 390.16 : x
  2. Step 2: Convert to fraction form
    1,211.90/1,818.16 = 390.16/x
  3. Step 3: Cross multiply
    1,211.90x = 1,818.16 × 390.16
  4. Step 4: Simplify right side
    1,211.90x = 709,367.78
  5. Step 5: Solve for x
    x = 709,367.78/1,211.90
  6. Step 6: Final answer
    x = 585.33

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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.