Home / 1,690.12-2,331.75-991.36

Finding the Fourth Proportional to 1,690.12, 2,331.75 and 991.36

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Solution

The fourth proportional to 1,690.12, 2,331.75 and 991.36 is: 1,367.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,690.12 : 2,331.75 = 991.36 : x
  2. Step 2: Convert to fraction form
    1,690.12/2,331.75 = 991.36/x
  3. Step 3: Cross multiply
    1,690.12x = 2,331.75 × 991.36
  4. Step 4: Simplify right side
    1,690.12x = 2,311,603.68
  5. Step 5: Solve for x
    x = 2,311,603.68/1,690.12
  6. Step 6: Final answer
    x = 1,367.72

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1.5x scale

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.