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Finding the Fourth Proportional to 1,991.80, 2,987.80 and 758.98

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Solution

The fourth proportional to 1,991.80, 2,987.80 and 758.98 is: 1,138.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,991.80 : 2,987.80 = 758.98 : x
  2. Step 2: Convert to fraction form
    1,991.80/2,987.80 = 758.98/x
  3. Step 3: Cross multiply
    1,991.80x = 2,987.80 × 758.98
  4. Step 4: Simplify right side
    1,991.80x = 2,267,671.08
  5. Step 5: Solve for x
    x = 2,267,671.08/1,991.80
  6. Step 6: Final answer
    x = 1,138.50

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1.5x scale

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.