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Finding the Fourth Proportional to 811.47, 1,119.47 and 644.71

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Solution

The fourth proportional to 811.47, 1,119.47 and 644.71 is: 889.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.47 : 1,119.47 = 644.71 : x
  2. Step 2: Convert to fraction form
    811.47/1,119.47 = 644.71/x
  3. Step 3: Cross multiply
    811.47x = 1,119.47 × 644.71
  4. Step 4: Simplify right side
    811.47x = 721,733.21
  5. Step 5: Solve for x
    x = 721,733.21/811.47
  6. Step 6: Final answer
    x = 889.42

Related Problems

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Half scale
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Double scale
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Similar ratio
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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.