Home / 1,421.76-2,131.20-652.80

Finding the Fourth Proportional to 1,421.76, 2,131.20 and 652.80

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Solution

The fourth proportional to 1,421.76, 2,131.20 and 652.80 is: 978.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.76 : 2,131.20 = 652.80 : x
  2. Step 2: Convert to fraction form
    1,421.76/2,131.20 = 652.80/x
  3. Step 3: Cross multiply
    1,421.76x = 2,131.20 × 652.80
  4. Step 4: Simplify right side
    1,421.76x = 1,391,247.36
  5. Step 5: Solve for x
    x = 1,391,247.36/1,421.76
  6. Step 6: Final answer
    x = 978.54

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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.