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Finding the Fourth Proportional to 806.64, 1,216.74 and 780.72

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Solution

The fourth proportional to 806.64, 1,216.74 and 780.72 is: 1,177.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.64 : 1,216.74 = 780.72 : x
  2. Step 2: Convert to fraction form
    806.64/1,216.74 = 780.72/x
  3. Step 3: Cross multiply
    806.64x = 1,216.74 × 780.72
  4. Step 4: Simplify right side
    806.64x = 949,933.25
  5. Step 5: Solve for x
    x = 949,933.25/806.64
  6. Step 6: Final answer
    x = 1,177.64

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.