Home / 1,415.20-2,122.80-1,312.80

Finding the Fourth Proportional to 1,415.20, 2,122.80 and 1,312.80

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Solution

The fourth proportional to 1,415.20, 2,122.80 and 1,312.80 is: 1,969.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,415.20 : 2,122.80 = 1,312.80 : x
  2. Step 2: Convert to fraction form
    1,415.20/2,122.80 = 1,312.80/x
  3. Step 3: Cross multiply
    1,415.20x = 2,122.80 × 1,312.80
  4. Step 4: Simplify right side
    1,415.20x = 2,786,811.84
  5. Step 5: Solve for x
    x = 2,786,811.84/1,415.20
  6. Step 6: Final answer
    x = 1,969.20

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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.