Home / 1,421.67-2,129.63-690.69

Finding the Fourth Proportional to 1,421.67, 2,129.63 and 690.69

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Solution

The fourth proportional to 1,421.67, 2,129.63 and 690.69 is: 1,034.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.67 : 2,129.63 = 690.69 : x
  2. Step 2: Convert to fraction form
    1,421.67/2,129.63 = 690.69/x
  3. Step 3: Cross multiply
    1,421.67x = 2,129.63 × 690.69
  4. Step 4: Simplify right side
    1,421.67x = 1,470,910.69
  5. Step 5: Solve for x
    x = 1,470,910.69/1,421.67
  6. Step 6: Final answer
    x = 1,034.64

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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.