Home / 2,815.20-4,222.80-840.90

Finding the Fourth Proportional to 2,815.20, 4,222.80 and 840.90

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Solution

The fourth proportional to 2,815.20, 4,222.80 and 840.90 is: 1,261.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,815.20 : 4,222.80 = 840.90 : x
  2. Step 2: Convert to fraction form
    2,815.20/4,222.80 = 840.90/x
  3. Step 3: Cross multiply
    2,815.20x = 4,222.80 × 840.90
  4. Step 4: Simplify right side
    2,815.20x = 3,550,952.52
  5. Step 5: Solve for x
    x = 3,550,952.52/2,815.20
  6. Step 6: Final answer
    x = 1,261.35

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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.