Home / 1,386.20-2,079.70-412.32

Finding the Fourth Proportional to 1,386.20, 2,079.70 and 412.32

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Solution

The fourth proportional to 1,386.20, 2,079.70 and 412.32 is: 618.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.20 : 2,079.70 = 412.32 : x
  2. Step 2: Convert to fraction form
    1,386.20/2,079.70 = 412.32/x
  3. Step 3: Cross multiply
    1,386.20x = 2,079.70 × 412.32
  4. Step 4: Simplify right side
    1,386.20x = 857,501.90
  5. Step 5: Solve for x
    x = 857,501.90/1,386.20
  6. Step 6: Final answer
    x = 618.60

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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.