Home / 1,987.17-2,980.77-1,121.28

Finding the Fourth Proportional to 1,987.17, 2,980.77 and 1,121.28

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Solution

The fourth proportional to 1,987.17, 2,980.77 and 1,121.28 is: 1,681.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,987.17 : 2,980.77 = 1,121.28 : x
  2. Step 2: Convert to fraction form
    1,987.17/2,980.77 = 1,121.28/x
  3. Step 3: Cross multiply
    1,987.17x = 2,980.77 × 1,121.28
  4. Step 4: Simplify right side
    1,987.17x = 3,342,277.79
  5. Step 5: Solve for x
    x = 3,342,277.79/1,987.17
  6. Step 6: Final answer
    x = 1,681.93

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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.