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Finding the Fourth Proportional to 1,218.13, 1,681.02 and 720.76

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Solution

The fourth proportional to 1,218.13, 1,681.02 and 720.76 is: 994.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,218.13 : 1,681.02 = 720.76 : x
  2. Step 2: Convert to fraction form
    1,218.13/1,681.02 = 720.76/x
  3. Step 3: Cross multiply
    1,218.13x = 1,681.02 × 720.76
  4. Step 4: Simplify right side
    1,218.13x = 1,211,611.98
  5. Step 5: Solve for x
    x = 1,211,611.98/1,218.13
  6. Step 6: Final answer
    x = 994.65

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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.