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Finding the Fourth Proportional to 818.39, 1,128.91 and 486.92

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Solution

The fourth proportional to 818.39, 1,128.91 and 486.92 is: 671.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.39 : 1,128.91 = 486.92 : x
  2. Step 2: Convert to fraction form
    818.39/1,128.91 = 486.92/x
  3. Step 3: Cross multiply
    818.39x = 1,128.91 × 486.92
  4. Step 4: Simplify right side
    818.39x = 549,691.38
  5. Step 5: Solve for x
    x = 549,691.38/818.39
  6. Step 6: Final answer
    x = 671.68

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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.