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Finding the Fourth Proportional to 2,138.60, 3,208.35 and 657.70

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Solution

The fourth proportional to 2,138.60, 3,208.35 and 657.70 is: 986.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,138.60 : 3,208.35 = 657.70 : x
  2. Step 2: Convert to fraction form
    2,138.60/3,208.35 = 657.70/x
  3. Step 3: Cross multiply
    2,138.60x = 3,208.35 × 657.70
  4. Step 4: Simplify right side
    2,138.60x = 2,110,131.80
  5. Step 5: Solve for x
    x = 2,110,131.80/2,138.60
  6. Step 6: Final answer
    x = 986.69

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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.