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Finding the Fourth Proportional to 728.46, 1,086.23 and 642.12

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Solution

The fourth proportional to 728.46, 1,086.23 and 642.12 is: 957.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.46 : 1,086.23 = 642.12 : x
  2. Step 2: Convert to fraction form
    728.46/1,086.23 = 642.12/x
  3. Step 3: Cross multiply
    728.46x = 1,086.23 × 642.12
  4. Step 4: Simplify right side
    728.46x = 697,486.80
  5. Step 5: Solve for x
    x = 697,486.80/728.46
  6. Step 6: Final answer
    x = 957.48

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.