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Finding the Fourth Proportional to 772.40, 1,157.40 and 669.20

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Solution

The fourth proportional to 772.40, 1,157.40 and 669.20 is: 1,002.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.40 : 1,157.40 = 669.20 : x
  2. Step 2: Convert to fraction form
    772.40/1,157.40 = 669.20/x
  3. Step 3: Cross multiply
    772.40x = 1,157.40 × 669.20
  4. Step 4: Simplify right side
    772.40x = 774,532.08
  5. Step 5: Solve for x
    x = 774,532.08/772.40
  6. Step 6: Final answer
    x = 1,002.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.