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Finding the Fourth Proportional to 823.12, 1,135.03 and 645.75

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Solution

The fourth proportional to 823.12, 1,135.03 and 645.75 is: 890.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    823.12 : 1,135.03 = 645.75 : x
  2. Step 2: Convert to fraction form
    823.12/1,135.03 = 645.75/x
  3. Step 3: Cross multiply
    823.12x = 1,135.03 × 645.75
  4. Step 4: Simplify right side
    823.12x = 732,945.62
  5. Step 5: Solve for x
    x = 732,945.62/823.12
  6. Step 6: Final answer
    x = 890.45

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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.