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Finding the Fourth Proportional to 855.81, 1,285.70 and 491.49

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Solution

The fourth proportional to 855.81, 1,285.70 and 491.49 is: 738.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.81 : 1,285.70 = 491.49 : x
  2. Step 2: Convert to fraction form
    855.81/1,285.70 = 491.49/x
  3. Step 3: Cross multiply
    855.81x = 1,285.70 × 491.49
  4. Step 4: Simplify right side
    855.81x = 631,906.24
  5. Step 5: Solve for x
    x = 631,906.24/855.81
  6. Step 6: Final answer
    x = 738.37

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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.