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Finding the Fourth Proportional to 778.60, 1,075.50 and 648.28

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Solution

The fourth proportional to 778.60, 1,075.50 and 648.28 is: 895.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.60 : 1,075.50 = 648.28 : x
  2. Step 2: Convert to fraction form
    778.60/1,075.50 = 648.28/x
  3. Step 3: Cross multiply
    778.60x = 1,075.50 × 648.28
  4. Step 4: Simplify right side
    778.60x = 697,225.14
  5. Step 5: Solve for x
    x = 697,225.14/778.60
  6. Step 6: Final answer
    x = 895.49

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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.