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Finding the Fourth Proportional to 1,321.92, 1,985.04 and 812.16

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Solution

The fourth proportional to 1,321.92, 1,985.04 and 812.16 is: 1,219.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,321.92 : 1,985.04 = 812.16 : x
  2. Step 2: Convert to fraction form
    1,321.92/1,985.04 = 812.16/x
  3. Step 3: Cross multiply
    1,321.92x = 1,985.04 × 812.16
  4. Step 4: Simplify right side
    1,321.92x = 1,612,170.09
  5. Step 5: Solve for x
    x = 1,612,170.09/1,321.92
  6. Step 6: Final answer
    x = 1,219.57

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.