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Finding the Fourth Proportional to 891.39, 1,230.19 and 513.40

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Solution

The fourth proportional to 891.39, 1,230.19 and 513.40 is: 708.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.39 : 1,230.19 = 513.40 : x
  2. Step 2: Convert to fraction form
    891.39/1,230.19 = 513.40/x
  3. Step 3: Cross multiply
    891.39x = 1,230.19 × 513.40
  4. Step 4: Simplify right side
    891.39x = 631,579.55
  5. Step 5: Solve for x
    x = 631,579.55/891.39
  6. Step 6: Final answer
    x = 708.53

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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.