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Finding the Fourth Proportional to 1,245.12, 1,718.30 and 685.62

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Solution

The fourth proportional to 1,245.12, 1,718.30 and 685.62 is: 946.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,245.12 : 1,718.30 = 685.62 : x
  2. Step 2: Convert to fraction form
    1,245.12/1,718.30 = 685.62/x
  3. Step 3: Cross multiply
    1,245.12x = 1,718.30 × 685.62
  4. Step 4: Simplify right side
    1,245.12x = 1,178,100.85
  5. Step 5: Solve for x
    x = 1,178,100.85/1,245.12
  6. Step 6: Final answer
    x = 946.17

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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.