Home / 1,243.80-1,862.28-1,128.60

Finding the Fourth Proportional to 1,243.80, 1,862.28 and 1,128.60

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Solution

The fourth proportional to 1,243.80, 1,862.28 and 1,128.60 is: 1,689.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,243.80 : 1,862.28 = 1,128.60 : x
  2. Step 2: Convert to fraction form
    1,243.80/1,862.28 = 1,128.60/x
  3. Step 3: Cross multiply
    1,243.80x = 1,862.28 × 1,128.60
  4. Step 4: Simplify right side
    1,243.80x = 2,101,769.21
  5. Step 5: Solve for x
    x = 2,101,769.21/1,243.80
  6. Step 6: Final answer
    x = 1,689.80

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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.