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Finding the Fourth Proportional to 818.76, 1,129.91 and 641.93

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Solution

The fourth proportional to 818.76, 1,129.91 and 641.93 is: 885.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.76 : 1,129.91 = 641.93 : x
  2. Step 2: Convert to fraction form
    818.76/1,129.91 = 641.93/x
  3. Step 3: Cross multiply
    818.76x = 1,129.91 × 641.93
  4. Step 4: Simplify right side
    818.76x = 725,322.74
  5. Step 5: Solve for x
    x = 725,322.74/818.76
  6. Step 6: Final answer
    x = 885.88

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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.