Home / 1,421.07-1,960.32-979.20

Finding the Fourth Proportional to 1,421.07, 1,960.32 and 979.20

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Solution

The fourth proportional to 1,421.07, 1,960.32 and 979.20 is: 1,350.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.07 : 1,960.32 = 979.20 : x
  2. Step 2: Convert to fraction form
    1,421.07/1,960.32 = 979.20/x
  3. Step 3: Cross multiply
    1,421.07x = 1,960.32 × 979.20
  4. Step 4: Simplify right side
    1,421.07x = 1,919,545.34
  5. Step 5: Solve for x
    x = 1,919,545.34/1,421.07
  6. Step 6: Final answer
    x = 1,350.77

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.