Home / 1,987.28-2,980.86-1,121.60

Finding the Fourth Proportional to 1,987.28, 2,980.86 and 1,121.60

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Solution

The fourth proportional to 1,987.28, 2,980.86 and 1,121.60 is: 1,682.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,987.28 : 2,980.86 = 1,121.60 : x
  2. Step 2: Convert to fraction form
    1,987.28/2,980.86 = 1,121.60/x
  3. Step 3: Cross multiply
    1,987.28x = 2,980.86 × 1,121.60
  4. Step 4: Simplify right side
    1,987.28x = 3,343,332.58
  5. Step 5: Solve for x
    x = 3,343,332.58/1,987.28
  6. Step 6: Final answer
    x = 1,682.37

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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.