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Finding the Fourth Proportional to 779.88, 1,075.86 and 485.49

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Solution

The fourth proportional to 779.88, 1,075.86 and 485.49 is: 669.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.88 : 1,075.86 = 485.49 : x
  2. Step 2: Convert to fraction form
    779.88/1,075.86 = 485.49/x
  3. Step 3: Cross multiply
    779.88x = 1,075.86 × 485.49
  4. Step 4: Simplify right side
    779.88x = 522,319.27
  5. Step 5: Solve for x
    x = 522,319.27/779.88
  6. Step 6: Final answer
    x = 669.74

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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.