Home / 1,421.72-2,131.20-691.44

Finding the Fourth Proportional to 1,421.72, 2,131.20 and 691.44

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Solution

The fourth proportional to 1,421.72, 2,131.20 and 691.44 is: 1,036.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.72 : 2,131.20 = 691.44 : x
  2. Step 2: Convert to fraction form
    1,421.72/2,131.20 = 691.44/x
  3. Step 3: Cross multiply
    1,421.72x = 2,131.20 × 691.44
  4. Step 4: Simplify right side
    1,421.72x = 1,473,596.93
  5. Step 5: Solve for x
    x = 1,473,596.93/1,421.72
  6. Step 6: Final answer
    x = 1,036.49

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1.5x scale

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.