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Finding the Fourth Proportional to 1,640.80, 2,262.86 and 1,290.88

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Solution

The fourth proportional to 1,640.80, 2,262.86 and 1,290.88 is: 1,780.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,640.80 : 2,262.86 = 1,290.88 : x
  2. Step 2: Convert to fraction form
    1,640.80/2,262.86 = 1,290.88/x
  3. Step 3: Cross multiply
    1,640.80x = 2,262.86 × 1,290.88
  4. Step 4: Simplify right side
    1,640.80x = 2,921,080.72
  5. Step 5: Solve for x
    x = 2,921,080.72/1,640.80
  6. Step 6: Final answer
    x = 1,780.28

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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.