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Finding the Fourth Proportional to 811.90, 1,120.12 and 517.11

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Solution

The fourth proportional to 811.90, 1,120.12 and 517.11 is: 713.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.90 : 1,120.12 = 517.11 : x
  2. Step 2: Convert to fraction form
    811.90/1,120.12 = 517.11/x
  3. Step 3: Cross multiply
    811.90x = 1,120.12 × 517.11
  4. Step 4: Simplify right side
    811.90x = 579,225.25
  5. Step 5: Solve for x
    x = 579,225.25/811.90
  6. Step 6: Final answer
    x = 713.42

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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.