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Finding the Fourth Proportional to 811.76, 1,119.96 and 646.38

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Solution

The fourth proportional to 811.76, 1,119.96 and 646.38 is: 891.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.76 : 1,119.96 = 646.38 : x
  2. Step 2: Convert to fraction form
    811.76/1,119.96 = 646.38/x
  3. Step 3: Cross multiply
    811.76x = 1,119.96 × 646.38
  4. Step 4: Simplify right side
    811.76x = 723,919.74
  5. Step 5: Solve for x
    x = 723,919.74/811.76
  6. Step 6: Final answer
    x = 891.80

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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.