Home / 1,420.38-2,131.65-690.42

Finding the Fourth Proportional to 1,420.38, 2,131.65 and 690.42

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Solution

The fourth proportional to 1,420.38, 2,131.65 and 690.42 is: 1,036.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.38 : 2,131.65 = 690.42 : x
  2. Step 2: Convert to fraction form
    1,420.38/2,131.65 = 690.42/x
  3. Step 3: Cross multiply
    1,420.38x = 2,131.65 × 690.42
  4. Step 4: Simplify right side
    1,420.38x = 1,471,733.79
  5. Step 5: Solve for x
    x = 1,471,733.79/1,420.38
  6. Step 6: Final answer
    x = 1,036.15

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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.