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Finding the Fourth Proportional to 890.40, 1,228.66 and 517.40

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Solution

The fourth proportional to 890.40, 1,228.66 and 517.40 is: 713.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.40 : 1,228.66 = 517.40 : x
  2. Step 2: Convert to fraction form
    890.40/1,228.66 = 517.40/x
  3. Step 3: Cross multiply
    890.40x = 1,228.66 × 517.40
  4. Step 4: Simplify right side
    890.40x = 635,708.68
  5. Step 5: Solve for x
    x = 635,708.68/890.40
  6. Step 6: Final answer
    x = 713.96

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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.