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Finding the Fourth Proportional to 817.68, 1,221.35 and 770.30

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Solution

The fourth proportional to 817.68, 1,221.35 and 770.30 is: 1,150.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.68 : 1,221.35 = 770.30 : x
  2. Step 2: Convert to fraction form
    817.68/1,221.35 = 770.30/x
  3. Step 3: Cross multiply
    817.68x = 1,221.35 × 770.30
  4. Step 4: Simplify right side
    817.68x = 940,795.95
  5. Step 5: Solve for x
    x = 940,795.95/817.68
  6. Step 6: Final answer
    x = 1,150.57

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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.