Home / 1,340.80-2,011.20-905.60

Finding the Fourth Proportional to 1,340.80, 2,011.20 and 905.60

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Solution

The fourth proportional to 1,340.80, 2,011.20 and 905.60 is: 1,358.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,340.80 : 2,011.20 = 905.60 : x
  2. Step 2: Convert to fraction form
    1,340.80/2,011.20 = 905.60/x
  3. Step 3: Cross multiply
    1,340.80x = 2,011.20 × 905.60
  4. Step 4: Simplify right side
    1,340.80x = 1,821,342.72
  5. Step 5: Solve for x
    x = 1,821,342.72/1,340.80
  6. Step 6: Final answer
    x = 1,358.40

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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.