Home / 1,987.36-2,742-1,288.96

Finding the Fourth Proportional to 1,987.36, 2,742 and 1,288.96

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Solution

The fourth proportional to 1,987.36, 2,742 and 1,288.96 is: 1,778.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,987.36 : 2,742 = 1,288.96 : x
  2. Step 2: Convert to fraction form
    1,987.36/2,742 = 1,288.96/x
  3. Step 3: Cross multiply
    1,987.36x = 2,742 × 1,288.96
  4. Step 4: Simplify right side
    1,987.36x = 3,534,328.32
  5. Step 5: Solve for x
    x = 3,534,328.32/1,987.36
  6. Step 6: Final answer
    x = 1,778.40

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.