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Finding the Fourth Proportional to 1,218.37, 1,680.81 and 720.67

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Solution

The fourth proportional to 1,218.37, 1,680.81 and 720.67 is: 994.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,218.37 : 1,680.81 = 720.67 : x
  2. Step 2: Convert to fraction form
    1,218.37/1,680.81 = 720.67/x
  3. Step 3: Cross multiply
    1,218.37x = 1,680.81 × 720.67
  4. Step 4: Simplify right side
    1,218.37x = 1,211,309.34
  5. Step 5: Solve for x
    x = 1,211,309.34/1,218.37
  6. Step 6: Final answer
    x = 994.20

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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.