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Finding the Fourth Proportional to 811.78, 1,120.16 and 457.68

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Solution

The fourth proportional to 811.78, 1,120.16 and 457.68 is: 631.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.78 : 1,120.16 = 457.68 : x
  2. Step 2: Convert to fraction form
    811.78/1,120.16 = 457.68/x
  3. Step 3: Cross multiply
    811.78x = 1,120.16 × 457.68
  4. Step 4: Simplify right side
    811.78x = 512,674.83
  5. Step 5: Solve for x
    x = 512,674.83/811.78
  6. Step 6: Final answer
    x = 631.54

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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.