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Finding the Fourth Proportional to 1,075.20, 1,612.80 and 840.30

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Solution

The fourth proportional to 1,075.20, 1,612.80 and 840.30 is: 1,260.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,075.20 : 1,612.80 = 840.30 : x
  2. Step 2: Convert to fraction form
    1,075.20/1,612.80 = 840.30/x
  3. Step 3: Cross multiply
    1,075.20x = 1,612.80 × 840.30
  4. Step 4: Simplify right side
    1,075.20x = 1,355,235.84
  5. Step 5: Solve for x
    x = 1,355,235.84/1,075.20
  6. Step 6: Final answer
    x = 1,260.45

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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.