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Finding the Fourth Proportional to 818.43, 1,128.10 and 641.10

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Solution

The fourth proportional to 818.43, 1,128.10 and 641.10 is: 883.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.43 : 1,128.10 = 641.10 : x
  2. Step 2: Convert to fraction form
    818.43/1,128.10 = 641.10/x
  3. Step 3: Cross multiply
    818.43x = 1,128.10 × 641.10
  4. Step 4: Simplify right side
    818.43x = 723,224.91
  5. Step 5: Solve for x
    x = 723,224.91/818.43
  6. Step 6: Final answer
    x = 883.67

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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.