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Finding the Fourth Proportional to 744.72, 1,028.21 and 665.78

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Solution

The fourth proportional to 744.72, 1,028.21 and 665.78 is: 919.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    744.72 : 1,028.21 = 665.78 : x
  2. Step 2: Convert to fraction form
    744.72/1,028.21 = 665.78/x
  3. Step 3: Cross multiply
    744.72x = 1,028.21 × 665.78
  4. Step 4: Simplify right side
    744.72x = 684,561.65
  5. Step 5: Solve for x
    x = 684,561.65/744.72
  6. Step 6: Final answer
    x = 919.23

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Double scale
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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.