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Finding the Fourth Proportional to 1,857.39, 2,786.40 and 687.39

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Solution

The fourth proportional to 1,857.39, 2,786.40 and 687.39 is: 1,031.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,857.39 : 2,786.40 = 687.39 : x
  2. Step 2: Convert to fraction form
    1,857.39/2,786.40 = 687.39/x
  3. Step 3: Cross multiply
    1,857.39x = 2,786.40 × 687.39
  4. Step 4: Simplify right side
    1,857.39x = 1,915,343.50
  5. Step 5: Solve for x
    x = 1,915,343.50/1,857.39
  6. Step 6: Final answer
    x = 1,031.20

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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.